Set Includes4 Pieces window silent nylon pulley slot wheel sliding door fittings. Suitable for window and doors Sturdy MaterialThe window pulley is made of quality iron shell, and nylon wheel, sturdy and wear resistant Single Wheel Pulley Single wheel pulley design, roll smoothly, silent and low noise, metal axles window pulley is easy to push and pull Easy To InstallEasy to install and assemble, stable structure makes it not easy to loosen ApplicationThe door rollers are widely used for sliding door, window, cabinet, etc. Specification: Material: Iron, Nylon Size Chart:75mmx17mmx4mm/2.95inchx0.67inchx0.16inch Package Includes: 4 Pieces Sliding Door Window Pulley Note: Please allow slightly errors due to manual measurement and different monitors.