uxcell Plastic Head Knurled Clamping Knob Jig M6x15mm Male Thread 10pcs Black Product Name : ClampingKnob;Type : Screw On Head Diameter : 18mm /0.7";Thread Size : M6x15mm/0.24"x0.6"(D*L) Total Height : 26mm /1";Material : Metal,Plastic Color : Black;Weight : 77g Package Content : 10 x ClampingKnob