Specification: Material: Plastic Color: Black Inner Diameter: Approx. 1inch/2inch (25mm) Quantity: 2Pcs Uses: dedicated to ordinary dumbbell rods, barbells Features: Strong and durable plastic. Designed for Bumper Plate use, Olympic lifting, and platform lifting workouts. Great quality collar clamps for barbell training. Exceptional durability，made from robust and durable material for long lasting use. They will fit all standard Hole 1"(25mm) weightlifting barbells or dumbbell bars. Keep weight plates securely and safely while lifting. Quick and easy to clamp and release for fast changeover of plates. Package Included: 2 x Barbell Lock Collars