PHS-W series Microprocessor pH/mV meter, PHS-25CW, 3CW, 3BW. The ... can be used conveniently.Two Points Push-Button Calibration:PHS-W series with two points calibration function, it will prompt pH ... Power RequirementsDC9V, using AC adapters, 220VAC, 50Hz Dimensions210(L)×205(W)×65(H)mm Weight1.5kg