The RAM-334-1U consists of a double socket arm, 3.625″ square base with the VESA hole pattern and stainless steel double u-bolt base that will fit pipes from 0.75″ to 1″ in diameter. The VESA base contains a 75mm X 75mm hole pattern. Designed into the mount is a 1.5″ diameter patented rubber ball and socket system with adjustment points at both socket ends of the arm. Rubber ball and socket technology allows for almost infinite adjustment and perfect viewing angles. U-Bolt Dimensions: Accommodates rails from 0.75″ to 1″ in diameter. Material: Powder Coated Marine Grade Aluminum Ball Size: 1.5″ Rubber Ball Size Note: The „U” in the part number reflects product packaged in poly bag.