Many DIY 3D printer makers are using idler pulleys based on 3D Printed wheels. Inaccurate printed idler decrease printing quality and create vibrations since the outside diameter of is not to rotation axis. Other makers are using double bearings with stationary washers clamped from both side. This solution is not since there is friction between the moving belt to the stationary washers. Our Aluminum Idler Pulley is a simple and inexpensive solution for this problem. Features - Color: Shown in the pictures. - Material: Alluminum. - Size:Approx. 1.8 x 1 x 1cm. - with maximum endurance for durability. - Work with 6mm wide GT2 timing belt, they will work perfectly with GT2 pulley-belt sets. - timing blet pulley, use with 16T 3mm bore idler pulley. - Widely used in milling machine, gear shaper, drilling machine, CNC engine lathe, hobbing machine or other machinery transmission occasions. Package list: 5 x GT2 8mm Bore Aluminum Timing Belt Idler Pulley for 3D Printer 6mm Width Timing Belt