Dream's Trihat is a hihat with three cymbals. When you play, you're only using two at the same time, but they open up for several combination possibilities, and that is what is clever about this hihat.
This hihat comes in two types: Diversity & Elements
Elements (which we have here) consists of:
Dream 14" Contact Hihat Top (804 grams)
Dream 14" Energy Hihat Top (1088 grams)
Dream 14" Bliss Hihat Bottom (998 grams)
In the video, you hear them combined like this:
1: Top: Contact - Bottom: Bliss
2: Top: Energy - Bottom: Bliss
3: Top: Contact - Bottom: Energy
This hihat includes a 14" bag and an extra hihat clutch (the thing that keeps the upper hihat stuck on the hihat stand).
The clutch prevents you from constantly having to reattach the hihat on the stand.