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. The *9 represents baseplates that are adaptable to Blue Ox tow bars with a 3-prong clevis. Demco's 9518302 Classic Baseplate is compatible with 2013 to 2017 Buick Enclave models.