Dixon was the brand those clutches started to get advertised recently.
Basically it's a Billdidit design - I've bought their Coady Clutch (I actually bought the Coady Combo) some months ago, it's a super cool design. Many consider this thing the best drop clutch on the market. I agree it's superb but actually have very limited experience with other clutches, but I'm 100% satisfied with it and won't look elsewhere. (I need a 2nd one now, having started using a 2nd set of hihats recently though.)
Here's the "initial" product/manufacturer website:
If you search for "Coady Clutch
" on this forum you'll find more info, this clutch has already been discussed.
One minor thing though... The design itself is great and works like a charm. But I noticed that the overall height is a bit massive, and the hihat bar on one of my hihat stand is a bit short so when I install the Coady Clutch there is no excess bar visible on the top of the clutch due to the height of the clutch design. In my setup I can get away with it, but there wasn't much space left.
PS: The amount of tightening on those 6 top screws sets the ease of drop action. I tightened those screws a little more than they came from stock as I was hearing a slight clicking sound when operating the hihat with the foot. Now this clicking sound has gone but the drop function is a bit stiffer now. You have to experiment for yourself and find a setting which will work for you.