Uxcell a15081800ux0908 M5 x 30mm Round Head Screw On Thumbscrews Knurled Knob Grips 12 Pcs, Product Name : clamping knob;type : screw on Head diameter : 15mm / 0.59";thread diameter : 5mm/ 0.2"(M10) Thread length : 30mm / 1.18";Total length : 41mm/ 1.6" Color : black, Silver Tone;material : metal, plastic Weight : 79G;Package Content : 12 pcs x clamping knob