metal locking knob, strong locking force, , , not easy to aging, ?skid designed, better hand feeling. Bottom /4 inch screw hole, compatible with most tripods or monopods on the market. Aluminum alloy material, CNC integrated forming, anodic oxidation , strong stability. Top /4 inch screw, compatible with most cameras in the market, motion cameras, etc. Small size and lightweight, easy to carry and store, convenient to use.