Medium Arm: The 2.25" ball double socket arm (medium arm) with an overall length of 8.44" Sturdy & Durable: The 2.25" ball medium arm is made of heavy duty solid marine-grade aluminum alloy with powder-coated to ensure reliability and strength in the most challenging environments Wide Application: Compatible with RAM Mounts & VAZESWIN all D size 2.25" ball components Universal Compatibility: Compatible with other 2.25" ball heavy duty device holders, such as: fish finder mounts, chartplotter mounts, navigator mounts, tablet mounts, marine electronic mounts, depth finder mounts, etc. The double socket arm (medium arm) with an overall length of 8.44"