It's a safety 'keeper' for the scope because it detaches with the slightest movement of the claw base. I've had other guns with claw mounts that required at least some effort to take the scope off and this one's almost like a set trigger.
The gun gets used a lot and I didn't want to worry about bumping the base on a branch or something and losing the scope and crazy expensive rings, so I sewed it up the 'keeper' mainly for peace of mind. I paid for rings once and never want to do that again, would cost more than I paid for the gun! Sewed it with 3/8" webbing with two 3/8" side release buckles.
