HIT Fitness Lock Jaw Collars are made from premium durable materials and are suitable for use with any standard Olympic barbell sleeve. Benefits: Corrosion resistant Prevents weight plates from slipping or moving during sets Can be used during high impact exercise movements Sold in pairs Compatible with all traditional Olympic barbells and many specialized barbells Secure locking clamp mechanism Will not damage plates, barbells, or surrounding equipment The design of these particular Lock-Jaw collars is unique to HIT Fitness and provides athletes with a secure barbell loading mechanism. These collars make it very quick and easy to safely secure weight plates to an Olympic barbell and ensures that the plates will not move on the barbell plate sleeve during exercises. The lock jaw collars are also designed in a manner that protects the barbell itself from scratches and aesthetic damage which commonly occurs when using regular barbell collars. Steel material Stiff locking Red coating Black clips Suitable for 50mm barbells only