Leofoto 22mm Arca Mini Screw-Knob Clamp Black. It features a shoe mount a 1/4''-20 mounting thread and an Arca-Swiss dovetail clamp that's secured by a knob. A common scenario is attaching it to a cage that has a built-in Arca dovetail. Attach it this way via the Arca clamp and then attach an accessory to the shoe mount or 1/4''-20 thread an accessory such as an articulating arm. Another example is attaching it via the 1/4''-20 thread to a matching 1/4''-20 screw on a monopod or selfie stick and then mounting a compatible cage or something else onto the Arca clamp. Specifications for Leofoto DC-22 22mm Arca Mini Screw-Knob Clamp: Manufacturer: Leofoto Color: Black Quantity: 1 Features of Leofoto DC-22 22mm Mini Screw-Knob Clamp - Arca Compatible Aluminum CNC Machining Package Contents: Leofoto DC-22 22mm Mini Screw-Knob Clamp - Arca Compatible Leofoto DC-22: DC-22 22mm Arca Mini Screw-Knob Clamp Black