M8x20mm Thread 40mm Dia Star Head Screw Clamping Knob Grips 5Pcs Weight: 157g; Product Name: Clamping Knob Main Material: Plastic,Metal; Package Content: 5Pcs x Clamping Knob Main Color: Silver Tone,Black; Star Head Diameter: 40mm/1.6" Thread Length: 20mm/0.8"; Thread Diameter: 8mm/0.3" Total Length: 45mm/1.8"