1、This mechanism is hidden behind the track, gently and quietly grabbing your barn door, similar to a soft closed drawer slide that is a great safe way to reduce the impact of the door on the end of the track. 2、This product is designed for one-way operation. It appears in pairs, one for the left side and one for the right side. 3、You should install 2 products on each side and then the door will stop gently when it is opened and closed. 4、Ensure that the door hits the door side without noise or rebound. 5、Suitable for all types of slides and metal box drawers Features: This mechanism is hidden behind the track, gently and quietly grabbing your barn door, similar to a soft closed drawer slide that is a great safe way to reduce the impact of the door on the end of the track. This product is designed for one-way operation. It appears in pairs, one for the left side and one for the right side. You should install 2 products on each side and then the door will stop gently when it is opened and closed. Ensure that the door hits the door side without noise or rebound. Suitable for all types of slides and metal box drawers Constructed with premium material, sturdy and available for long service life. Specifications: Material: Steel Maximum tension: 10-25n Service life: 50,000-8,000 times Maximum load: 20KGS-80KGS Color: Black Size: Approx.31x1.9x2.2cm/12.2x0.75x0.87in Package Includes: 1 x Damper 1 x Regulator 3 x Screws 2 x Wrenches 2 x S-shaped accessories Note: 1. Please allow 1-3mm error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, and item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.