 This increases the ProMaster's air efficiency and cycle speed as well as reducing the amount of recoil felt when firing.Another advantage to adding the ICDU cylinder is the hammer can be removed out of the back of the gun, resulting in an easier maintenance process for the user.Other popular upgrades are replacement high pressure regulators, low pressure regulators and valves that offer higher air flow and consistency, resulting in higher paintball velocities at lower air pressures, thus increasing the ProMaster's efficiency.