Extang Tonneau Cover Features: Quick Release+; L-Rail+ System; No Measure Install L-Rails+ Create Self-Centering Lid System TuffKlamp+ Attachment System No Drilling; No Damage Can Be Easily Used w/One Hand Monster Bows+ And ClickLock+ Corners MaxCare Warranty; 10 Year Tarp; Lifetime Frame Height: 6.00 Width: 10.00 Length: 78.00 Fitment: 2007/GMC/Sierra 2500 HD Classic/WT Standard Cab Pickup 2-Door/8.1L 496Cu. In. V8 GAS OHV Naturally Aspirated::Bed Length = 78.0, Bed Side = Fleetside^^2007/GMC/Sierra 2500 HD Classic/WT Standard Cab Pickup 2-Door/6.6L 6599CC 403Cu. In. V8 DIESEL OHV Turbocharged::Bed Length = 78.0, Bed Side = Fleetside^^2007/GMC/Sierra 2500 HD Classic/WT Standard Cab Pickup 2-Door/6.0L 5967CC 364Cu. In. V8 GAS OHV Naturally Aspirated::Bed Length = 78.0, Bed Side = Fleetside^^2007/GMC/Sierra 2500 HD Classic/WT Exte...