Using quality steel, the SMAI Barbell Spring Collars are a budget friendly option for securing weights. Trusted by Olympic weightlifters and bodybuilders for decades, these barbell collars are sold in a pair and made to be a simple and effective option to add to your training. Specifications Quality steel Easy-to-use design Used on Olympic Bars Collar dimension: 50mm Sold as a pair SMAI Collars are compatible with the following: D540-86-Bearing D540-Youth D540-80-Bearing