National Hardware Steel Double Box Rail Splice Brackets 300 lb (Pack of 2)With the National hardware 300 lbs. Galvanized steel double box rail splice bracket, you can install the box rails you need to begin installation of your new door. The adjustable bracket is made of galvanized steel for durability and holds up to 300 lbs. safely. UPC: 038613104754 Manufacturer Part No: N104 752 Material: Steel Product Type: Double Box Rail Splice Brackets Width: 5 3 4 in. Number in Package: 1 pk Capacity: 300 lb Length: 2 in. Brand