Timing belt kit is is designed specifically for linear movement and precision, high positioning accuracyTiming pulley with 20 teeth which minimizes the risk of the belt slippingThe timing belt is made of premium rubber, more durable and flexibleCome with 5m GT2 timing belt , 8 pcs timing pulley, as as an Hex wrench choices for Reprap, Prusa, MendelMax,3D PrinterAt least six teeth in contact with the pulley at a given time. This will reduce the possibility of sliding. GT2 pulley and belt are used , and the with rounded teeth, which ensures that the belt tooth smoothly and accurately into the pulley groove.Anti-backlash timing belt pulley with 20 teeth is one of the best choices for 3d printer construction.COLOR: black&silverGT2 Timing belt: Material: RubberLength: 5m Width: 6mm Pitch: 2mmGT2 timing pulley wheel: Material: Aluminum Diameter: 16 mm Hole: 5mm Teeth: 20Package Included: 1 * 5m GT2 timing belt 8 * 20T timing pulley 1 * Hexagon wrenchOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.