Due to the growing demand for Nitrogen/Compressed Air systems we decided to develop a kit that would offer the best efficiency at a set low pressure. Although the stock A-5 will operate on nitrogen without the kit, there is very little advantage over CO2 because the internals are not designed for a high pressure system. When we design a gun to operate on CO2 we have to take into consideration a large variety of pressures ranging from an empty bottle all the way up to 3,000psi, where the rupture disc fails. CO2 changes pressure as the temperature changes, the higher the temperature the higher the pressure. Granted we cannot cover the entire pressure range, so we shoot for the most common operating pressures. These pressures are 300-2,000psi. In order to have a gun function through this pressure range, without a large velocity variation, we sacrifice some efficiency and overall gun comfort. With a high pressure system we are only working with one set operating pressure. Through research and testing we have found the most efficient pressure to be between 300-400psi. By changing to a low pressure configuration we can obtain better efficiency, less recoil, and a more consistent shot to shot velocity. With the operating pressure around 350psi the valve opens much easier, but also requires a larger amount of gas flow to maintain ball velocity. Along with the valve modifications the low pressure chamber supports these flow and volume demands.