8mm Bore Aluminum Timing Pulley3mm Pitch 24 Teeth 15mm Wide Belt Groove for 3D printer HTD3M Description 3mm pitch (HTD) 24 teeth 8mm bore 15mm width timing Belt With 2 set screw to secure to the stepper motor shaft. One pulley Most Common Application8mm shaft stepper motor and fits 15mm width timing belt 3mm Pitch HTD-3MUsed on Kossel Delta and other similar 3D Printers RepRap