There seems to be no possibility to get the rzslider html element when reacting on a slideEnded event. The event variable does not contain any useful information about the slider element.
I wanted to change the opacity of the slider when a user moves a specific slider. Here's my workaround: I changed the $emit of this event from:
Original code: this.scope.$emit("slideEnded")
to:
Updated code: this.scope.$emit("slideEnded", this)

In my eventhandling function I am now able to get the id of the slider element like this:
$scope.$on("slideEnded", function(event, args) {
var compositeSliderId = args.attributes.id;
...
});

Question: Is there another possibility to do this that I overlooked? If no, do you think it's feasible to integrate my workaround?