Features: 1. Completely adjustable rollers ensuring smooth and safe sliding. 2. It can be used with 3inch thickness doors, suitable for all brands of barn door. 3. Easy for installation, fix 2 screws on the floor bottom plate, adjust and tighten. 4. Built-in bearing provides ultra-smooth rolling, convenient to use. 5. Carbon steel frame with black surface, screw matching for maximum durability. Specifications: Material: Carbon Steel Color: Black Optional Type: Single Roller, Double Roller, Heighten Single Roller Thickness: Approx. 0.5cm / 0.2in Suitable: for 76mm / 3in thickness sliding door Size: Approx. 10.5 * 4 * 5cm / 4.1 * 1.6 * 2in Package List: 1 * Floor Guide 1 * Bag of Screw Accessory Note: 1. Please allow 1-3mm error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.1Completely adjustable rollers ensuring smooth and safe sliding. 2It can be used with 3inch thickness doors, suitable for all brands of barn door. 3Easy for installation, fix 2 screws on the floor bottom plate, adjust and tighten. 4Built-in bearing provides ultra-smooth rolling, convenient to use. 5Carbon steel frame with black surface, screw matching for maximum durability.