The Olympic barbell collar, also known as a pressure ring collar with spin lock, is a sophisticated mechanical clamp. Weighing in at five pounds, in this country and two and half kilos (5.5 pounds) in metric countries, the Olympic barbell collar fits over the end of the revolving 2-inch sleeve on each end of the standardized Olympic weightlifting bar. Olympic plates are loaded onto the barbell and the collar is then slid onto the barbell until it nuzzles the weight plates. At that point, a two part procedure is enacted: the wingnut clamps are tightened, ensuring no sliding of the barbell plates, and finally, the round spindle is spun, tightening the payload/plates inward, thereby ensuring plates are forced inward. The goal is to secure the plates evenly thereby ensuring a balanced payload for the lifter.