Our 1-1/2" coupling-to-coupling adapter allows smooth, safe 360-degree rotation for your display. Thick steel plate is welded to each of the swivel plates and milled to insure mating surface smoothness. The two surfaces are secured by an 8-point, hard steel bolt and self-locking nut for continuous rotation without de-threading. Properly installed, it supports up to 275 lbs. Allen bolt for the couplings and jam nuts for the pipes are included.