A set of 10 pulleys. Made of metal and plastic, with ball bearings inside for smooth movement and durability. Perfect for your cabinets, bookcases, display cases and other office furniture. Note: The wheel diameter is 19mm, please check the size of your furniture before purchasing to make sure the pulleys meet your needs. This caster is specially designed for U-shaped tracks. Diameter of each wheel: 1.9cm. Width between rollers. Inner dimensions: 2cm. The roller has a small bracket that allows you to properly position and wedge the door before securing it. Even doors 2-50 meters high slide smoothly Although small in size, it is enough to support about 40 kg Note: The data are all measured manually, please allow 1-3 cm error Due to differences in light and display, there may be some color differences, please refer to the actual item received.