White Rodgers NBE 3-1/2BA-02 Thermostatic Expansion Valve NXT-R SERIES THERMOSTATIC EXPANSION VALVE, REFRIGERANT CODE B (R-448A, R-449A, R-452A), CHARGE CODE A (MED & LOW TEMP), 3-1/2 TON, 3/8" X 1/2" ODF STRAIGHT THRU, SUPERHEAT ADJUSTABLE, NO INTERNAL CHECK, EXTERNAL EQUALIZER, NO BLEED, CAP TUBE 30"