MATCC Weight Lifting Standard Size Screw Collar Spin Lock Chrome Plated Single Collar Fitment: For 1"/2.5cm bars only (standard size). Spinlock Collars are easy and quick way to move your plates around. Keep weight plates securely and safely while lifting. Save $2.00 off purchase of 2 items;Save$5.00 off purchase of 4 items. Package: 1Pcs Standard Barbell Bar Spin-lock