GT2 timing belts and compatible pulleys(GT2 pulley) are popular choices for RepRaps and RepStraps.
Designed specifically for linear motion.
For best performance you want at least 6 teeth in contact with the pulley at any given time. That minimizes the chance of the belt slipping, and helps reduce backlash even further. In practice that means you want a minimum of a 12 teeth pulley, and I usually try to get at least 32 teeth.
Size: Approx. 5 * 3 * 0.8cm/ 2 * 1.2 * 0.31 inch (L*W*H);Material: Alluminum
Package - GT2 Aluminum timing belt pulley x 5;Set Screw x 10;Allen Key x 1