The Wyr-Grid 18" (457.2 mm FiberRunner QuikLock® Trapeze Bracket is made of steel and is black powder coated. It is 12.2" (309.9 mm high, 18.7" (475.0 mm long, 2.3" (58.4 mm wide, and 18.7" (475.0 mm deep. It attaches to the Wyr-Grid 18" (457.2 mm wide pathway to support-secondary FiberRunner-x-or-x-channel above the Wyr-Grid pathway. It adjusts 6.6" (166.6 mm to 9.9" (251.0 mm over the top surface of the Wyr-Grid pathway. It comes in standard packages of one.