Our locking barbell collar are made of high-strength nylon and reinforced plastic with injection molded pressure pads.The durable cast body and high-pressure grip pads make the collar virtually indestructible! Our barbell collars are more secure than most traditional spring clips and are also easier to both lock-on and remove. They are perfect for crossfit training, strength training, weightlifting and any workout using standard barbells. Not suggested used for dumbbell. Easy to use,one click lock design for easy install and remove , snap-latch design to keep you safe.Lightweight, easy to carry and store.