Blue Ox baseplates are designed to be shock absorbing and integrated into the individual bumper frame or unibody. Created to let the baseplate torsion or flex, similar to a receiver hitch, so it absorbs the forces of towing rather than just transferring the forces to the frame of the towed vehicle. Easy installation with the hardware and easy to read instructions included. Tow bar fastens easily with two pins. Lifetime warranty. Fits: 1984 Trooper II  1985 Trooper II  1986 Trooper II  1987 Trooper II  1988 Trooper II  1989 Trooper II  1990 Trooper II  1991 Trooper II