The Mega-Truss Dolly easily holds truss for transport or storage. The 5 inch aluminum C channel has CNC milled cutouts for truss to ride in. It is important to secure the trusses tightly to the Mega-Truss Dolly with an E-Clip ratchet strap before moving. The two 4" × 2" heavy duty castors are rated for 480 pounds each. A pair of Mega-Truss Dollies will carry up to 1900 total pounds of truss. Mega-Truss Dollies are available in a variety of sizes, with additional sizes available upon request. Dollies are sold as a set or pair. E-Clip ratchet straps are available and are sold separately, Part # MTDESTRAP. OPTIONAL MEGA-COUPLERS -Add the optional Mega-Couplers to hold the bottom truss directly to the Mega-Truss Dolly. The optional Mega-Couplers prevent the Mega Truss Dolly from tipping when loading or unloading. ( See Photo ) There is a special part number for the Mega-Truss Dollies with the optional couplers. Also, these Mega-Couplers require special hardware depending upon where they are placed.