Description: The set 3D printer kit includes a timing belt, pulleys, screws and a wrench. A timi ng belt is a non-slipping mechanical drive belt. This is synchronous belt is designed for 3D printer. Belt pulley is an 3D printer accessory for 6mm wide belt . As an synchronous pulley wheel, you will find it perfect for 3D printer or similar projects. Features: Belt is made of rubber material, very flexible. Pulley adopt high quality aluminum alloy, excellently machined, finished smoothly. Belt is 6mm wide, low noise, high wear resistance. Excellent proces s, good quality and durable. Perfect choice for building a 3D printer or similar projects. Specifications: Type: 2GT Material: Rubber(belt), aluminum alloy(pulley) Pulley Inner Diameter: 8mm / 0.3in Belt Width: 6mm / 0.23in Belt Length: 5m / 16.4ft Weight: 87g(approx.) Package Includes: 8 x 2GT Timing Pulleys 1 x Timing Belt 16 x Screws 1 x Wrench Note: Please allow 1-3mm error due to manual measurement. Thanks for your understanding.