Prost Professional Aluminum Alloy Quick Shoe Plate Adapter with 1/4 3/8 inches Screw for DSLR Camera Camcorder Tripod Monopod,Compatible with Manfrotto 501HDV 503HDV 701HDV 577/519/561/Q5 Can be used with tripod, rail, stabilizer and different devices, for Photography. Rubber mat on surface prevent wearing of camera, compatible for Manfrotto 501HDV 503HDV 701HDV 577/519/561/Q5 With red safety pin prevent sliding accidently which can keep your camera camcorder safe Locking knob makes quick shoe plate more stable and prevent loosing and sliding Holes in the adapter plate enable more connecting possibilities