Demco's baseplates are designed specifically to respect the beauty and design of your vehicle. Demco's engineers use Finite Elemental Analysis (FEA) when testing our baseplates for strength, functionality, and durability. On most vehicles, they won't protrude out, hang below or rise above your bumper or grill. Bolts permanently to the chassis of the towed vehicle and provides a secure, reliable attachment point for all Demco tow bars. The *4 represent baseplates that are concealed through the bumper opening. Demco's 9517321 Classic Baseplate is compatible with 2011 to 2019 Chevrolet and GMC 2500 Heavy Duty and 3500 Heavy Duty Series Pickups with four wheel drive.