Ultradyne UD Dynalock Barricade Arca-Pic Clamp Black. When engaged the Dynalock does not allow any forward or back movement of the Barricade. It can be attached to ARMS 17S mounting Clamps including Ultradyne Arca and Arca-Pic Clamps making the Dynalock Barricade rock solid. Specifications for Ultradyne UD Dynalock Barricade Arca-Pic Clamp: Manufacturer: Ultradyne Color: Black Finish: Hardcoat anodize Fabric/Material: 6061-T6 Aluminum Length: 2.83 in Width: 1.95 in Package Contents: Ultradyne UD Dynalock Barricade Arca-Pic Clamp Ultradyne UD20072: UD Dynalock Barricade + Arca-Pic Clamp Black