Applying same style on multiple elements in mootool

I have been lately trying to see how to apply same style on multiple elements using mootools. Now, mootools does provide a method for that known as Fx.Elements. Now, if you want to apply only 1 style, use tween on Fx.Elements and if you want to change multiple styles, then use morph. The issue is if you visit the official documentation here you will see that it requires you to know the total number of elements and you have to mention the index number as well. However, what if you want to apply same effect on all the elements and you don't know how many elements there are. The method to do that is fairly simple. Use the following code;

$$('.simpleBox').morph({
height: 50,
opacity: 0.3
});


where simpleBox is the name of the class which is applied on all the elements on which you wanna apply the style/effect. See the following url to see it in action;

http://www.jsfiddle.net/xwUFN/2/