The Control Freak Bag was one of the last pieces added to the Trifecta Handgun Rest puzzle. Looking back it should have been one of the first. Our groups tightened up immediately after implementing the first prototype. Several versions later I am proud to say we have the best rear bag in the handgun hunting business. We fill our bag with Just the right amount of Poly Beads to take as much vibration out of the shot, prior to the bullet leaving the barrel. The Control Freak Bag can be used with any type of handgun rest. We use a sewn-on hook and Loop system. We provide the hook (scratchy side), you provide the loop.