Used in jet pump water systems Maintains proper charge in conventional tanks Prolongs pump life by reducing frequency of cycling No AV-45: Part No 15770, 80 Maximum Tank Gallons, 1/4"" FIP No AV-100: Part No 15770, 120 Maximum Tank Gallons, 3/8""FIP No 15679: Part No 15679, 42 Maximum Tank Gallons, 1/4"" FIP No AV-100: Part No 15770 120 Maximum Tank Gallons 3/8""