3 - in - 1 Temperature, TDS, and pH Meter. Large, easy - to - read LCD screen. Water - resistant for use in humid environments. pH range 0.00 - 14.00. TDS range 0 - 19990 MG/ Lppm) Temperature range 5 - 50C. Battery 4 x 1.5V AG13. Automatic Temperature Compensation (ATC) 0 - 50C. For any inquiries, you can contact us at 002002002047310707