1 Inch collars: the barbell anti-skid collar is suitable for 1 inch/ 25 mm standard weight lifting barbells or dumbell bars Convenient and safe: the dumbbell rod nuts are easy and quick to move your plates, they also keep plates securely and safely while lifting, using is a of fitness safety Operational safety: the dumbbell screw clamp with rubber edged anti slip tightening collar ensures that it is securely and safely attached to the dumbbell or barbell bar; Smooth contoured finger tip handles quick and easy installing and removing from dumbbells or barbells Durable material: the barbell collars are made of quality material for lasting use, you will receive 2 anti-skid collars made of iron and 4 anti-skid collars made of plastic Widely applied: the collar clamp is suitable for barbell, dumbell, weight lifting and etc.; You can also send them as a gift to your friends and families, especially sport lovers Colour:Black+silver Material:Plastic + Steel Package Contents: 2x washer nut (25mm) 4x environmental protection nut (25mm) Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.