The ball base consists of a B size 1" TPU ball, connected to a M6 x 1.0 male threaded steel post. TPU over-molded ball joint are anti-slip and wear-resistant for durability and reliability in the most demanding environments. The 1'' ball base allows for connection to RAM & BRCOVAN any B size 1 inch ball double socket arm. The threaded hole must contain the following dimensions for this base to fit: M6 x 1.0 pitch. The 1 inch ball adapter with M6 x 1.0 threaded post compatible with RAM Mounts B size 1'' ball double socket arm