uxcell 40mm Star Head M8x30mm Male Thread Screw on Clamping Knob Black 3pcs Weight: 100g; Product Name: Clamping Knob Main Material: Plastic, Metal; Package Content: 3 x Star Head Knob Main Color: Black, Silver Tone; Thread Size: 8 x 30mm/ M8 x 1.2"(D*L) Star Head Dia: 40mm/ 1.6"; Total Height: 50mm/ 2" Head Shape: 5 Point Star