Ultradyne UD Arca-Pic Clamp Black. It is also compatible with the ARMS 17S mounting system which is widely used by popular accessories including those from Ultradyne. This clamp is lightweight easy to use and provides a strong hold for your accessories. Specifications for Ultradyne UD Arca-Pic Clamp: Manufacturer: Ultradyne Color: Black Finish: Hardcoat anodize Fabric/Material: 6061-T6 Aluminum Length: 1.85 in Width: 2.43 in Last Chance: Yes Package Contents: Ultradyne UD Arca-Pic Clamp Ultradyne UD20012: UD Arca-Pic Clamp Black