diff --git a/src/ol/overlay.js b/src/ol/overlay.js
index e555b8c3d4..9e7beac57a 100644
--- a/src/ol/overlay.js
+++ b/src/ol/overlay.js
@@ -36,32 +36,38 @@ ol.Overlay = function(options) {
   ol.Object.call(this);
 
   /**
-   * @private
-   * @type {number|string|undefined}
+   * @protected
+   * @type {olx.OverlayOptions}
    */
-  this.id_ = options.id;
+  this.options = options;
 
   /**
-   * @private
+   * @protected
+   * @type {number|string|undefined}
+   */
+  this.id = options.id;
+
+  /**
+   * @protected
    * @type {boolean}
    */
-  this.insertFirst_ = options.insertFirst !== undefined ?
+  this.insertFirst = options.insertFirst !== undefined ?
     options.insertFirst : true;
 
   /**
-   * @private
+   * @protected
    * @type {boolean}
    */
-  this.stopEvent_ = options.stopEvent !== undefined ? options.stopEvent : true;
+  this.stopEvent = options.stopEvent !== undefined ? options.stopEvent : true;
 
   /**
-   * @private
+   * @protected
    * @type {Element}
    */
-  this.element_ = document.createElement('DIV');
-  this.element_.className = options.className !== undefined ?
+  this.element = document.createElement('DIV');
+  this.element.className = options.className !== undefined ?
     options.className : 'ol-overlay-container ' + ol.css.CLASS_SELECTABLE;
-  this.element_.style.position = 'absolute';
+  this.element.style.position = 'absolute';
 
   /**
    * @protected
@@ -70,28 +76,28 @@ ol.Overlay = function(options) {
   this.autoPan = options.autoPan !== undefined ? options.autoPan : false;
 
   /**
-   * @private
+   * @protected
    * @type {olx.OverlayPanOptions}
    */
-  this.autoPanAnimation_ = options.autoPanAnimation ||
+  this.autoPanAnimation = options.autoPanAnimation ||
     /** @type {olx.OverlayPanOptions} */ ({});
 
   /**
-   * @private
+   * @protected
    * @type {number}
    */
-  this.autoPanMargin_ = options.autoPanMargin !== undefined ?
+  this.autoPanMargin = options.autoPanMargin !== undefined ?
     options.autoPanMargin : 20;
 
   /**
-   * @private
+   * @protected
    * @type {{bottom_: string,
    *         left_: string,
    *         right_: string,
    *         top_: string,
    *         visible: boolean}}
    */
-  this.rendered_ = {
+  this.rendered = {
     bottom_: '',
     left_: '',
     right_: '',
@@ -100,29 +106,29 @@ ol.Overlay = function(options) {
   };
 
   /**
-   * @private
+   * @protected
    * @type {?ol.EventsKey}
    */
-  this.mapPostrenderListenerKey_ = null;
+  this.mapPostrenderListenerKey = null;
 
   ol.events.listen(
-      this, ol.Object.getChangeEventType(ol.Overlay.Property_.ELEMENT),
+      this, ol.Object.getChangeEventType(ol.Overlay.Property.ELEMENT),
       this.handleElementChanged, this);
 
   ol.events.listen(
-      this, ol.Object.getChangeEventType(ol.Overlay.Property_.MAP),
+      this, ol.Object.getChangeEventType(ol.Overlay.Property.MAP),
       this.handleMapChanged, this);
 
   ol.events.listen(
-      this, ol.Object.getChangeEventType(ol.Overlay.Property_.OFFSET),
+      this, ol.Object.getChangeEventType(ol.Overlay.Property.OFFSET),
       this.handleOffsetChanged, this);
 
   ol.events.listen(
-      this, ol.Object.getChangeEventType(ol.Overlay.Property_.POSITION),
+      this, ol.Object.getChangeEventType(ol.Overlay.Property.POSITION),
       this.handlePositionChanged, this);
 
   ol.events.listen(
-      this, ol.Object.getChangeEventType(ol.Overlay.Property_.POSITIONING),
+      this, ol.Object.getChangeEventType(ol.Overlay.Property.POSITIONING),
       this.handlePositioningChanged, this);
 
   if (options.element !== undefined) {
@@ -151,7 +157,7 @@ ol.inherits(ol.Overlay, ol.Object);
  */
 ol.Overlay.prototype.getElement = function() {
   return /** @type {Element|undefined} */ (
-    this.get(ol.Overlay.Property_.ELEMENT));
+    this.get(ol.Overlay.Property.ELEMENT));
 };
 
 
@@ -161,7 +167,7 @@ ol.Overlay.prototype.getElement = function() {
  * @api
  */
 ol.Overlay.prototype.getId = function() {
-  return this.id_;
+  return this.id;
 };
 
 
@@ -173,7 +179,7 @@ ol.Overlay.prototype.getId = function() {
  */
 ol.Overlay.prototype.getMap = function() {
   return /** @type {ol.PluggableMap|undefined} */ (
-    this.get(ol.Overlay.Property_.MAP));
+    this.get(ol.Overlay.Property.MAP));
 };
 
 
@@ -185,7 +191,7 @@ ol.Overlay.prototype.getMap = function() {
  */
 ol.Overlay.prototype.getOffset = function() {
   return /** @type {Array.<number>} */ (
-    this.get(ol.Overlay.Property_.OFFSET));
+    this.get(ol.Overlay.Property.OFFSET));
 };
 
 
@@ -198,7 +204,7 @@ ol.Overlay.prototype.getOffset = function() {
  */
 ol.Overlay.prototype.getPosition = function() {
   return /** @type {ol.Coordinate|undefined} */ (
-    this.get(ol.Overlay.Property_.POSITION));
+    this.get(ol.Overlay.Property.POSITION));
 };
 
 
@@ -211,7 +217,7 @@ ol.Overlay.prototype.getPosition = function() {
  */
 ol.Overlay.prototype.getPositioning = function() {
   return /** @type {ol.OverlayPositioning} */ (
-    this.get(ol.Overlay.Property_.POSITIONING));
+    this.get(ol.Overlay.Property.POSITIONING));
 };
 
 
@@ -219,10 +225,10 @@ ol.Overlay.prototype.getPositioning = function() {
  * @protected
  */
 ol.Overlay.prototype.handleElementChanged = function() {
-  ol.dom.removeChildren(this.element_);
+  ol.dom.removeChildren(this.element);
   var element = this.getElement();
   if (element) {
-    this.element_.appendChild(element);
+    this.element.appendChild(element);
   }
 };
 
@@ -231,22 +237,22 @@ ol.Overlay.prototype.handleElementChanged = function() {
  * @protected
  */
 ol.Overlay.prototype.handleMapChanged = function() {
-  if (this.mapPostrenderListenerKey_) {
-    ol.dom.removeNode(this.element_);
-    ol.events.unlistenByKey(this.mapPostrenderListenerKey_);
-    this.mapPostrenderListenerKey_ = null;
+  if (this.mapPostrenderListenerKey) {
+    ol.dom.removeNode(this.element);
+    ol.events.unlistenByKey(this.mapPostrenderListenerKey);
+    this.mapPostrenderListenerKey = null;
   }
   var map = this.getMap();
   if (map) {
-    this.mapPostrenderListenerKey_ = ol.events.listen(map,
+    this.mapPostrenderListenerKey = ol.events.listen(map,
         ol.MapEventType.POSTRENDER, this.render, this);
     this.updatePixelPosition();
-    var container = this.stopEvent_ ?
+    var container = this.stopEvent ?
       map.getOverlayContainerStopEvent() : map.getOverlayContainer();
-    if (this.insertFirst_) {
-      container.insertBefore(this.element_, container.childNodes[0] || null);
+    if (this.insertFirst) {
+      container.insertBefore(this.element, container.childNodes[0] || null);
     } else {
-      container.appendChild(this.element_);
+      container.appendChild(this.element);
     }
   }
 };
@@ -273,8 +279,8 @@ ol.Overlay.prototype.handleOffsetChanged = function() {
  */
 ol.Overlay.prototype.handlePositionChanged = function() {
   this.updatePixelPosition();
-  if (this.get(ol.Overlay.Property_.POSITION) && this.autoPan) {
-    this.panIntoView_();
+  if (this.get(ol.Overlay.Property.POSITION) && this.autoPan) {
+    this.panIntoView();
   }
 };
 
@@ -294,7 +300,7 @@ ol.Overlay.prototype.handlePositioningChanged = function() {
  * @api
  */
 ol.Overlay.prototype.setElement = function(element) {
-  this.set(ol.Overlay.Property_.ELEMENT, element);
+  this.set(ol.Overlay.Property.ELEMENT, element);
 };
 
 
@@ -305,7 +311,7 @@ ol.Overlay.prototype.setElement = function(element) {
  * @api
  */
 ol.Overlay.prototype.setMap = function(map) {
-  this.set(ol.Overlay.Property_.MAP, map);
+  this.set(ol.Overlay.Property.MAP, map);
 };
 
 
@@ -316,7 +322,7 @@ ol.Overlay.prototype.setMap = function(map) {
  * @api
  */
 ol.Overlay.prototype.setOffset = function(offset) {
-  this.set(ol.Overlay.Property_.OFFSET, offset);
+  this.set(ol.Overlay.Property.OFFSET, offset);
 };
 
 
@@ -329,28 +335,28 @@ ol.Overlay.prototype.setOffset = function(offset) {
  * @api
  */
 ol.Overlay.prototype.setPosition = function(position) {
-  this.set(ol.Overlay.Property_.POSITION, position);
+  this.set(ol.Overlay.Property.POSITION, position);
 };
 
 
 /**
  * Pan the map so that the overlay is entirely visible in the current viewport
  * (if necessary).
- * @private
+ * @protected
  */
-ol.Overlay.prototype.panIntoView_ = function() {
+ol.Overlay.prototype.panIntoView = function() {
   var map = this.getMap();
 
   if (!map || !map.getTargetElement()) {
     return;
   }
 
-  var mapRect = this.getRect_(map.getTargetElement(), map.getSize());
+  var mapRect = this.getRect(map.getTargetElement(), map.getSize());
   var element = /** @type {!Element} */ (this.getElement());
-  var overlayRect = this.getRect_(element,
+  var overlayRect = this.getRect(element,
       [ol.dom.outerWidth(element), ol.dom.outerHeight(element)]);
 
-  var margin = this.autoPanMargin_;
+  var margin = this.autoPanMargin;
   if (!ol.extent.containsExtent(mapRect, overlayRect)) {
     // the overlay is not completely inside the viewport, so pan the map
     var offsetLeft = overlayRect[0] - mapRect[0];
@@ -384,8 +390,8 @@ ol.Overlay.prototype.panIntoView_ = function() {
 
       map.getView().animate({
         center: map.getCoordinateFromPixel(newCenterPx),
-        duration: this.autoPanAnimation_.duration,
-        easing: this.autoPanAnimation_.easing
+        duration: this.autoPanAnimation.duration,
+        easing: this.autoPanAnimation.easing
       });
     }
   }
@@ -397,9 +403,9 @@ ol.Overlay.prototype.panIntoView_ = function() {
  * @param {Element|undefined} element The element.
  * @param {ol.Size|undefined} size The size of the element.
  * @return {ol.Extent} The extent.
- * @private
+ * @protected
  */
-ol.Overlay.prototype.getRect_ = function(element, size) {
+ol.Overlay.prototype.getRect = function(element, size) {
   var box = element.getBoundingClientRect();
   var offsetX = box.left + window.pageXOffset;
   var offsetY = box.top + window.pageYOffset;
@@ -420,7 +426,7 @@ ol.Overlay.prototype.getRect_ = function(element, size) {
  * @api
  */
 ol.Overlay.prototype.setPositioning = function(positioning) {
-  this.set(ol.Overlay.Property_.POSITIONING, positioning);
+  this.set(ol.Overlay.Property.POSITIONING, positioning);
 };
 
 
@@ -430,9 +436,9 @@ ol.Overlay.prototype.setPositioning = function(positioning) {
  * @protected
  */
 ol.Overlay.prototype.setVisible = function(visible) {
-  if (this.rendered_.visible !== visible) {
-    this.element_.style.display = visible ? '' : 'none';
-    this.rendered_.visible = visible;
+  if (this.rendered.visible !== visible) {
+    this.element.style.display = visible ? '' : 'none';
+    this.rendered.visible = visible;
   }
 };
 
@@ -461,7 +467,7 @@ ol.Overlay.prototype.updatePixelPosition = function() {
  * @protected
  */
 ol.Overlay.prototype.updateRenderedPosition = function(pixel, mapSize) {
-  var style = this.element_.style;
+  var style = this.element.style;
   var offset = this.getOffset();
 
   var positioning = this.getPositioning();
@@ -473,59 +479,69 @@ ol.Overlay.prototype.updateRenderedPosition = function(pixel, mapSize) {
   if (positioning == ol.OverlayPositioning.BOTTOM_RIGHT ||
       positioning == ol.OverlayPositioning.CENTER_RIGHT ||
       positioning == ol.OverlayPositioning.TOP_RIGHT) {
-    if (this.rendered_.left_ !== '') {
-      this.rendered_.left_ = style.left = '';
+    if (this.rendered.left_ !== '') {
+      this.rendered.left_ = style.left = '';
     }
     var right = Math.round(mapSize[0] - pixel[0] - offsetX) + 'px';
-    if (this.rendered_.right_ != right) {
-      this.rendered_.right_ = style.right = right;
+    if (this.rendered.right_ != right) {
+      this.rendered.right_ = style.right = right;
     }
   } else {
-    if (this.rendered_.right_ !== '') {
-      this.rendered_.right_ = style.right = '';
+    if (this.rendered.right_ !== '') {
+      this.rendered.right_ = style.right = '';
     }
     if (positioning == ol.OverlayPositioning.BOTTOM_CENTER ||
         positioning == ol.OverlayPositioning.CENTER_CENTER ||
         positioning == ol.OverlayPositioning.TOP_CENTER) {
-      offsetX -= this.element_.offsetWidth / 2;
+      offsetX -= this.element.offsetWidth / 2;
     }
     var left = Math.round(pixel[0] + offsetX) + 'px';
-    if (this.rendered_.left_ != left) {
-      this.rendered_.left_ = style.left = left;
+    if (this.rendered.left_ != left) {
+      this.rendered.left_ = style.left = left;
     }
   }
   if (positioning == ol.OverlayPositioning.BOTTOM_LEFT ||
       positioning == ol.OverlayPositioning.BOTTOM_CENTER ||
       positioning == ol.OverlayPositioning.BOTTOM_RIGHT) {
-    if (this.rendered_.top_ !== '') {
-      this.rendered_.top_ = style.top = '';
+    if (this.rendered.top_ !== '') {
+      this.rendered.top_ = style.top = '';
     }
     var bottom = Math.round(mapSize[1] - pixel[1] - offsetY) + 'px';
-    if (this.rendered_.bottom_ != bottom) {
-      this.rendered_.bottom_ = style.bottom = bottom;
+    if (this.rendered.bottom_ != bottom) {
+      this.rendered.bottom_ = style.bottom = bottom;
     }
   } else {
-    if (this.rendered_.bottom_ !== '') {
-      this.rendered_.bottom_ = style.bottom = '';
+    if (this.rendered.bottom_ !== '') {
+      this.rendered.bottom_ = style.bottom = '';
     }
     if (positioning == ol.OverlayPositioning.CENTER_LEFT ||
         positioning == ol.OverlayPositioning.CENTER_CENTER ||
         positioning == ol.OverlayPositioning.CENTER_RIGHT) {
-      offsetY -= this.element_.offsetHeight / 2;
+      offsetY -= this.element.offsetHeight / 2;
     }
     var top = Math.round(pixel[1] + offsetY) + 'px';
-    if (this.rendered_.top_ != top) {
-      this.rendered_.top_ = style.top = top;
+    if (this.rendered.top_ != top) {
+      this.rendered.top_ = style.top = top;
     }
   }
 };
 
 
 /**
- * @enum {string}
- * @private
+ * returns the options this Overlay has been created with
+ * @public
+ * @return {olx.OverlayOptions} overlay options
  */
-ol.Overlay.Property_ = {
+ol.Overlay.prototype.getOptions = function() {
+  return this.options;
+};
+
+
+/**
+ * @enum {string}
+ * @protected
+ */
+ol.Overlay.Property = {
   ELEMENT: 'element',
   MAP: 'map',
   OFFSET: 'offset',
diff --git a/test/spec/ol/overlay.test.js b/test/spec/ol/overlay.test.js
index a6c3fe002d..0b8ffde2d6 100644
--- a/test/spec/ol/overlay.test.js
+++ b/test/spec/ol/overlay.test.js
@@ -47,7 +47,7 @@ describe('ol.Overlay', function() {
     it('can be constructed with className', function() {
       var instance = new ol.Overlay({className: 'my-class'});
       expect(instance).to.be.an(ol.Overlay);
-      expect(instance.element_.className).to.be('my-class');
+      expect(instance.element.className).to.be('my-class');
     });
 
   });
@@ -98,9 +98,9 @@ describe('ol.Overlay', function() {
       });
       map.addOverlay(overlay);
       map.renderSync();
-      expect(overlay.element_.style.display).not.to.be('none');
+      expect(overlay.element.style.display).not.to.be('none');
       overlay.setVisible(false);
-      expect(overlay.element_.style.display).to.be('none');
+      expect(overlay.element.style.display).to.be('none');
     });
 
   });