Medium Arm: The double socket arm with an overall length of 5.7"(145 mm) Sturdy & Durable: The C size 1.5" ball medium arm is made of heavy duty solid aircraft-grade aluminum alloy with powder-coated to ensure reliability and strength in the most challenging environments Wide Application: Compatible with RAM Mounts & VAZESWIN all 1.5"(38.1 mm) ball mounting base components Universal Compatibility: Compatible with other 1.5" ball device holders, such as: fish finder mounts, chartplotter mounts, navigator mounts, tablet mounts, marine electronic mounts, depth finder mounts, etc. Made of powder-coated, aluminum alloy for durability and reliability in the most challenging environments