PH Controller pH Range -2 to 16 pH pH Accuracy +/-1 pH Resolution 0.01 pH ORP Range (mV) -1 999 to 1 999 mV ORP Accuracy +/-1 ORP Resolution (mV) 1 mV Display LCD Power Source 100 V AC to 240 V AC Output 4 to 20 mA Relay (2) SPDT Height 1.75 in Depth 4.25 in Width 3.33 in Manufacturers Warranty Length 1 yr