Yosoo 2pcs Digital Camera Tripod Quick Release Plate D Ring Captive 1/4"" D-Ring Steel Stainless Screw Connecting Adapter UNC for Camera Tripod Monopod Quick Release Plate (Type 1) 1. 1/4" metal male thread with a 4mm Hex Socket & hinged "D" Ring 2. D-ring with flat head screwdriver slot, can drive it by coin. 3. Material - Stainless Steel. Total Length: 21mm / 0.83 inch,Shaft Length: 17mm / 0.67 inch(Included thread) 4. The screw allows the fitment of different styles of plates to fit directl 5. Can be used with tripods, monopods, telescopes, ball heads, lens collars, lens plates etc.