This is 1'' (25.4mm) ball to 1'' (25.4mm) ball adapter, compatible with RAM Mounts and BRCOVAN any B size 1 inch ball double socket arm. Consists of two B size 1" balls connected by a 0.78" length post. When measured from ball center to ball center, the length is 1.69". Overall length 2.48''. Ball and post are made of 6061-T6 aluminum alloy for durability and reliability in the most demanding environments. CNC integral molding, solid structure. Anodized surface treatment, durable. The aluminum alloy double 1 inch ball adapter compatible with RAM Mounts & BRCOVAN any B size 1'' ball double socket arm. Ball and post are made of 6061-T6 aluminum alloy for durability and reliability in the most demanding environments. CNC integral molding, solid structure. Anodized surface treatment, durable.