These aluminum Barbell collars are constructed with Aircraft Grade Aluminum and provide a great option and upgrade to your existing worn or spring collars. A simple lever action is all that is needed to engage the collar onto your 50 mm Olympic bar. For use with Olympic, Crossfit, and functional lifters alike for repeated, High impact drops. Rubberized interior lining for superior grip, rigidity and protection for your bar. Comes in Anodized Red for a stunning color presentation.