SunwayFoto DDT-53 Subtend Clamp for Arca-Swiss QR Plates This Item Includes: SunwayFoto DDT-53 Subtend Clamp for Arca-Swiss QR Plates - Stainless Steel - 1/4"-20 Bushing Adapter - SunwayFoto 6 Year Warranty Anodized to a scratch-resistant, black finish Captive knob Safety stop relief grooves prevent your equipment from dropping accidently This clamp can be installed with a quick-release plate both on top and bottom side simultaneously