▶ The main body of the 1.5'' ball mount base is 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 inch ball bar clamp mount kit comes with three soft rubber ring inserts that provide a snug fit and protect the mounting surface. Three rubber ring diameters: 0.875" (22mm), 1" (25.4mm), 1.125" (28.6mm). The rubber ring can be increased or decreased according to the diameter of the round rails. The round rail mount base have a 1.26" (32mm) diameter mounting hole when without the rubber ring insert. | ▶ The 1.5'' ball rail mount accommodates handlebars or round rails 0.875 inch (22mm) / 1 inch (25.4mm) / 1.125 inch (28.6mm) / 1.26 inch (32mm) in diameter. An Allen key is included with the package to facilitate your installation. | ▶ The 1.5 inch ball tube clamp mount compatible with RAM Mounts and BRCOVAN any C size 1.5 inch ball double socket arm. Work for other devices with 1.5 inch swivel ball mounting pattern. Great for marine electronic mounts, fish finder mounts, GPS Chartplotter mounts, industrial tablet mount, industrial Monitor mount, navigation device mounts, camcorder mounts, rod holders and much more in a wide variety of applications. | ▶ Ideal for mounting on the handlebars of bicycles, motorcycles, scooters, and other round rails of compatible sizes.