The Custom Products barrel front is a must have if you are getting the CP 2 piece barrel or CP Barrel kit. The Custom Products barrel front comes in a total of 16 different colors as well as 5 different sizes. You can choose from a length between 10 and 21 inches for the front. The barrel backs are all the exact same length, so the front you purchase will control the total length of the barrel. The Custom Products barrel front lengths are the total size of the barrel as opposed to just the length of the tip.