Made from hard plastic this collar clamps on all 2 bars with ease. Quality collar to hold plates on bars. Troy 2 Muscle Clamp Collars - Pair (AOMC) - Leave it to Troy Barbell to design an easy yet effective barbell collar. This 2 Muscle Clamp collar clamps quickly and is gentle on bars. Includes: (2) Troy Muscle Clamp Collars (1 pair). Easy to use Olympic collars for all Olympic bars. Weight: 1 lb. per pair.