The RAM-201U-B consists of a short double socket arm that accommodates 1.5" C size ball bases, device holders, and adapters. With an overall length 3.56", this is the shortest RAM® double socket arm size. The easy to adjust knob allows for near-infinite adjustability for your connected device.

3-Hole 120-Degree: 1.812" Diameter, Plate Size: 2.5" Diameter, Ball/Socket Size: C Size (1.5"), Weight Capacity: 4 lbs, Materials: Marine-grade aluminum.   The RAM-202U, marine grade aluminum base, consists of a 1.5" diameter rubber ball connected to a flat 2.5" diameter base. This mount has pre-drilled holes, including the universal AMPS hole pattern.