The anti-theft 1'' ball double socket arm 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 With anti-theft knob design. Package come with a special wrench to adjust this secure knob. This design prevents the device attached to the double socket arm from being easily removed. Provides extra security for your device. The secure knob of double socket arm made of PA66+GF30% material Medium Arm: Overall length 3.54 inch (90mm) Compatible with RAM Mounts & BRCOVAN any B size 1 inch ball components, including mounting bases and device holders Suitable for other 1" ball device mounts, such as bike phone mounts, motorcycle phone holders, action camera mounts, navigation mounts, marine electronic mounts, etc. The anti-theft aluminum alloy double socket arm medium arm compatible with RAM Mounts B size 1" ball components. Made of 6061-T6 aluminum alloy for durability and reliability in the most demanding environments. CNC integral molding, solid structure. Anodized surface treatment, smooth surface, durable. (Medium Arm)