uxcell Plastic Star Head M6 x 30mm Female Thread Clamping Knob 6 Pcs Black Product Name : ClampingKnob;Type : Screw On Head Diameter : 30mm / 1.2";Female Thread Dia. : M6 Total Height : 23mm /0.9";Material : Metal,Plastic Color : Black;Weight : 91g Package Content : 6PcsxClampingKnob