Valken Ultra Rig Low Pressure Output Tank Kit (150psi) Replacement Loader Parts In case you don't want Grips In case you don't want any optics the Tavor also features flip up front and rear back up sights While existing designs may require a low force to open the exhaust valve they are still bound by the need to overcome blowback using the speed and mass of the bolt which means that the valve has to be opened with a greater speed than is actually required Lightweight and durable aircraft grade aluminum construction the Valken Ultra Rig accepts input pressures up to 800psi allowing its use with most popular and widely available paintball style HPA systems