X-Grip 1 inch Adapter Ball The RAM-HOL-UN7-BALL consists of a 1 inch diameter rubber ball and hardware for attaching to the back of the RAM-HOL-UN7U universal X-Grip holder. Material: High Stength Composite Ball Size: 1 inch Rubber Ball inch B inch Size Please note: When attaching this to RAM-HOL-UN7, you need to remove the decal covering the hole first.