Timing belt pulley: -2gt timing belt pulley with 5mm bore , 20 teeth.. Mechanic belt: -perfect choice for building a 3d printer or similar projects. 20 teeth idler pulley: pulley drive gear is a perfect choice for building a 3d printer or similar projects. Timing belt idler pulley: -2gt aluminum timing pulley has shiny surface appearance and robust construction, longer working life.. Aluminum idler pulley: they are good replacement parts for old or broken 3d printer belt pulley..
