Usage Tips:Reliable material: made of polycarbonate, its nice wear resistance, flame retardancy and oxidation resistance can assist your 3D printer to complete its work well Broad compatibility: it's applicable for most DIY 3D printer's V slot aluminum profile, including, but not limited for , 3, Anet, etc. Nice expressiveness: these 3D printer wheels move smoothly, have low noise, have high printing accuracy, and can nicely increase the printing speed, they are useful accessories for 3D printers Wide range of uses: they are not only mainly applied for 3D printers, but also for engravers, hot wire machines, laser cutters, camera sliders, plasma cutters, robotics, furniture, and other DIY machines Size: Outer diameter: 24 mm Inner diameter: 5 mm Height: 11 mm Color: transparent Material: Transparent polycarbonate wheels Package Contents: 16 x 3D printer polycarbonate pulleys Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.