This ASV is found on the Ultima models VI and VII and is also found on some Ultima GRO50-4, GRO50-5, GRO50-ALK. It is also found on other Ultima models and on many other brands of RO systems. It shuts off the water supply to the membrane once the water pressure in the tank reaches approximately 45psi and turns on the water supply to the membrane once the water pressure in the tank drops to approximately 20psi. This kit includes tubing and extra fitting so it will fit most brands and models of RO systems. Replaces ASV100-BK, ASV2000N, [ASV2000N-(W), (B)], ASV2000W, ASV2000B.