That's one of Randy Edwards' Bow Fishing Slingshots (Falcon Archery). THe handle is dyed laminated hardwood. The "pouch" is a piece of bowstring with a paracord loop for shooting fiberglass fishing arrows. The $100 price tag is surprising. They used to sell at SlingshotsUSA for about $50 with a standard hardwood grip (poplar, IIRC), and the custom grip was like $20 or so extra (again, IIRC). Check out some of the vids:
Bow Fishing Slingshot
Bow Fishing Slingshot