1MR355M2 Binary Low Pressure Switch Fits: 1989 - 2006 Mack CH, CHN, CS, CM1MR355M2 Binary Low Pressure Switch Fits: 1989 2006 Mack CH, CHN, CS, CM OEM Numbers 1MR3550M, 20779144, 25131431 Specifications TYPE Normally Open LOW PRESSURE OPENS 28 PSI Falling Pressure LOW PRESSURE CLOSES 32 PSI Rising Pressure HIGH PRESSURE OPENS 335 psi Rising Pressure HIGH PRESSURE CLOSES 240 psi Falling Pressure THREAD SIZE M10 x 1. 25 * Made to OEM Specs To Provide A Direct Fitment & Easy Install! * Manufactured With High Grade Materials By