1) PH4V : Sensor for Old FCL2) PH5V : Sensor for 5x/5n/i5pH SENSOR (FOR OLD FCL)SKU: pH Sensor$0.00PriceProduct No*PH4VPH5VQuantity*Add to CartProduct InfoThe PH4V/PH5V is a sensor that measures hydrogen ions and water temperature. Specification Method Glass-Electrode Sensor Range 0~14 Resolution 0.01 Accuracy ±2.0% or ±0.03 Repeatability ±2.0% Response time <30 sec