Features: Over time, the e track mounted on the wooden board may become loose, or if your cargo is too heavy, the E track might wobble. In such cases, a backing plate needs to be installed behind the board to secure the e track Application: Compatible with all standard universal e tracks. These plates are work for single or multiple e track mounts Specifications: Material: steel Size: 3 x 6 inches Package includes: 12 x E track backing plates 48 x Locking nuts 48 x Bolts 96 x Flat washers Notes: Manual measurement, please allow slight errors on size. The color may exist a slight difference due to different screen displays.