PACKAGE INCLUDE: there are 2 pack 2 inch solid spinlock collars in the box, exactly fit your 2” Olympic weight barbells and dumbbell of 2 inches, strong and sturdy enough, so you need not worry the barbell comes off, very convenient and be at ease when you lift the barbell SUPER MATERIAL: each of them is made of high end steel and upscale black plastic, ultra-soft protective cover make them assembly and disassembly convenient and save time, very easy to lock your barbell WAY TO USE: the barbell clip adopt ergonomic design, Long press the button to expand the diameter, until it reaches the right position of the barbell, then release the button to fix the barbell, save effort, and expand and reduce the diameter through the principle of leverage