The Quick Tray Pro Center Hangers are used to support Quick Tray Pro product with a single threaded rod. It should be used with up to 1/2-inch threaded rod (obtain locally). There is only one rod needed to suspend the tray. The snap-on attachment holds the Quick Tray Pro cable tray securely without the need for nuts and bolts. It is for use with 4- to 24-inch (102- to 610-mm) tray widths. It also can be used for multiple-level installations; 1/2-inch threaded rod recommended.