The DC-22 is an Arca Swiss clamp with ¼-inch screw hole that you clamp onto, for example, an Arca Swiss compatible lens support rail or L-plate. This allows you to easily attach an accessory with a ¼-inch thread to your L-bracket.
Cold shoe adapter
Also, the DC-22 has a cold shoe adapter where you can place, for example, a flash. With this Arca Swiss clamp you can easily combine accessories. With the gray knob you can set the distance between the Arca Swiss clamp hooks. The clamp plate is 22mm wide. By using CNC aircraft aluminum the DC-22 clamp weighs only 22 grams.