The PROLOC blocker is the accessory to have when you store your bar at a public gym. When the PROLOC blocker is attached to your bar, from the middle of the bar to the end, it renders the bar USELESS. With a chain from the lock you can further secure it to other equiptment in the gym such as racks and weight trees. FIts any bar with collars ranging from 1.937" to 2.007" (Fits most bars, Fits all olympic bars) One Collar is included. Lock NOT included. Comes with an allen key that is stored within the collar. Comes in BLACK