Punching bag Uppercut Ring/Donut - UNFILLED. for Heavy Punching Bags Unfilled. This product is designed to attach on the heavy bag to practice Uppercuts. If it is lower down to the floor while being attached to the heavy bag, it reduces heavy bag movement. Made of top quality 22oz heavy duty polyester coated vinyl material. Weighs 14 lbs Note: This product would not fit to the heavy bags diameter less than 13 inches