Features:Suitable for sliding barn doors,keep the door bottom stable,prevent doors bottom swinging out when slides;align perfectly,goes smoothly; Advantages:Adjustable and Dual mounting methods,suitable for Both pre-grooved and non-grooved doors,1pc works for one Pre-grooved door,1pair clip for one Non-grooved door(dual mounting methods); Design:Easy to install,just secure to the floor,No door panel thickness limited; Installed on the floor to keep the door stable,prevent bottom swinging out when slides; Keeps sliding barn doors align perfectly,goes smoothly; Compact design,perfect for light mounting,keep safe; Unlimited door panel thickness; Dimension:1.77 inch L X 0.78 inch W X 0.9 inch H(45mm x 20mm x 23mm); Colour:Black Material:POM Package Contents: 6 pairs of floor rails 24 * mounting screws Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.