Pair of 1"/2" Pair Heavy Duty Barbell Collars Muscle Clamps Bar Black-standard Lock 1. Quick snap collars are a innovative design, superior durability and exceptional performance is perfect choice for any bar. 2. It was made of ABS and can hold heavier. 3. It is not so slip as metal collars. 4. One-hand fast installation and removal. 5. Solid injection molded frame