50mm OLYMPIC BAR END LOCK FOR PLATES Spring Lock Collars are designed to provide the most secure fit to any Olympic Barbell with a 2" diameter. They are developed from high grade steel so these collars are strong, durable and easy to use. Our set is sold as a pair and have a weight of 0.46KG per spring lock. These universal collars are designed for use with all standard 2" Olympic Weight Lifting Bars (4ft, 5ft, 6ft & 7ft variations) or 2" dumbbell bars. The spring loaded design allows for quick and easy plate changing.