The ball mount consists of a C size 1.5'' TPU ball connected to a 2" x 1.69" square plate. The square plate features industry-standard AMPS hole pattern with four pre-drilled holes at each corner The square plate made of 6061-T6 aluminum alloy material with CNC machining and iii grade hard anodized surface for durability and reliability in the most demanding environments. TPU over-molded ball head, non-slip and wear-resistant The 1.5'' ball mount base compatible with RAM Mounts & BRCOVAN any C size 1.5'' ball double socket arms. Work for other devices with 1.5 inch swivel ball mounting pattern. Compatible with Garmin devices The 4-Hole AMPS square plate base mount with 1.5 inch TPU ball. Compatible with RAM Mounts C size double socket arm. The square plate made of 6061-T6 aluminum alloy material with CNC machining and iii grade hard anodized surface for durability and reliability in the most demanding environments. TPU over-molded ball head, non-slip and wear-resistant.