8mm Bore Aluminum Timing Pulley 2mm Pitch 30 Teeth 6mm Wide Belt Groove for 3D printer GT28mm Bore Aluminum Timing Pulley 2mm Pitch 30 Teeth 6mm Wide Belt Groove for 3D printer GT2 2mm pitch (GT2) 30 teeth 8mm bore 6mm width timing Belt With 2 set screw to secure to the stepper motor shaft. One pulley Most Common Application 8mm shaft stepper motor and fits 6mm width timing belt 2mm Pitch Used on Kossel Delta and other similar 3D Printers RepRap