GT2 30T Transmission Pulley 4/5/6/6.35/7/8/10mm Inner Bore 11mm Width 2GT Tooth Belt Pulley for Engraving MachineProduct Name2GT-30T-BF Timing PulleyTeeth number30TTeeth Pitch 2mmBelt Width11mmInner Bore Diameter4/5/6/6.35/7/8/10mmTotal Height23mmScrews2xM4MaterialAluminium AlloyPackage2GT-30T-BF timing pulley with screws *1/2pcs