From Alesis Product Guide 2014: Dual Cymbal Hi-Hat Controller For DM10 / DM8 12” single-zone top and bottom cymbals Authentic hi-hat playability and feel Create open, half-open, closed, chick, and splash sounds Compatible with any standard hi-hat stand Includes top cymbal, bottom cymbal, clutch, and position sensor Patent pending technology For more: http://www.alesis.com/tradeshows/wnamm2014/alesis.html
Well, its hard to tell. What we do know is currently Alesis is looking for a new product manager (link) for their electronic drum division. On top of that, many Alesis edrum products are no longer being sold by the several large online retailers. Many of these online retailers are listing these items as discontinued.