【Built to Last】AOLISHENG fully extended heavy duty drawer runners are built for lasting durability, proven through more than 60,000 opening and closing tests while maintaining smooth operation. 【Smooth & Silent Heavy Duty Drawer Runners】Features double rows of solid carbon steel balls: Ø9.4mm for the outer rail and Ø7.8mm for the middle rail. Each ball is polished, cleaned, refined, and rust-treated. The drawer glides smoothly, quietly, and effortlessly, making daily life more comfortable. 【Triple Layer Rust Protection】Constructed from 2.5mm thick cold rolled steel, these heavy duty drawer runners feature a blue passivated galvanized coating. This surface treatment creates a robust barrier that shields the steel from air and moisture, significantly enhancing its resistance to corrosion, rust, and oxidation. As a result, the service life of the slides is extended by 3 to 5 times compared to standard alternatives. 【Installation Requirements】Size:48 inch, Load capacity: 180kg, Wideth: 76mm. You can choose the size of the heavy duty drawer runners according to the depth of the drawer. *The length of the slide should be ≤ The length of the drawer. Installation clearance: 19.2mm~19.7mm(Each). 【Product Type & Applications】These AOLISHENG heavy duty drawer runners feature a non-locking, non-removable design, making them a suitable and robust choice for various applications such as shelves, industrial drawers, toolboxes, RVs, and trucks., Manufacturer: AOLISHENG