The SIRUI Arca-type Pro Quick Release Plate TY-60 has a 1/4"-20 camera screw and features a rubberized surface for a more secure connection. It is compatible with the many other Arca-type quick release systems, such as Acratech, Foba, Graff and Wimberley. The two red buttons when inserted up, add a secondary security measure to prevent the camera or the lens from slipping off the plate, especially when it is tilted at an angle. SpecificationsMaterialAluminum AlloyCamera TypeAll CamerasBall Head TypeG-20 / K-20X / K-30XDimensions ( L x W x H ) 2.36 x 1.93 x 0.43 in/60 x 49 x 10.8 mmWeight 39.4 g / 1.39 oz