Description: This synchronous aluminum belt pulley is designed for 3D printer. It is an 3D printer accessory for 10mm wide belt. As an synchronous pulley wheel, you will find it perfect for 3D printer or similar projects. Specifications: Material: Aluminum Alloy Type: Smooth without teeth Height: 13mm / 0.511" Outer Diameter: 18mm / 0.708" Inner Diameter: 5mm / 0.196" Belt Width: 10mm / 0.393" Quantity: 5 Weight: 24g(approx.) Package Includes: 5 x Belt Pulleys Note: 1. Please allow 1-2mm error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard. 3. New-style and old-style are shipped randomly.