Keep your weights secure during workouts with the fast-locking Cortex Alpha Series Olympic Magnetic Collars. Made from commercial quality aluminium, these collars are built to last and offer superior clamping power. The high strength magnets make them easy to store on your rack or rig, making them easy to find when you next need them. The black interior lining also helps protect your bars, weights and collars. Compatible with any Olympic bar, dumbbell, or 50mm sleeve.