The PU-70 slide release 1/4;-20 thread spare or replacement part for Ballheads and other compatible clamps. Safe screw installed in both side to prevent of camera by accident. change of the screw different cameras. The PU-70 universal system has designed to be compatible with other . Suitable ball heads. Specification: Material: Metal Color: Black Length: 70mm/2.75inch Width: 38mm/1.49' (Universal width of QR s). Thickness: 10mm/0.39' (Universal Thickness of QR s) Mounting Screw Diameter: 1/4; (The Screw Size Connecting the QR and Camera) Compatibility: Package Includes: 1 Piece 70mm 1 Piece 1/4 inch Screw Note: Please 1-3mm differs due to manual measurement. Due to the different display and different light, the picture may not show the actual the . your understanding.