The pen ORP meter is professional and ideal tool for testing ORP and temperature of your water level. Suitable for aquarium pool and environment water. Features: Use to measure the amount of Oxidation Reduction Potential (ORP) level and temperature (C/ F). Double functions, measuring ORP and temperature. Clear LCD display with backlight. Apply in water sources, aquarium, hydroponics, spas, swimming pools and other water systems. Waterproof IP65 and replaceable sensor probe. Auto shut off. Compact and portable pen-type design. Easy to use and provides instant display of results. Specifications: Range: -1999mV 1999mV Temperature Range: -50 70(-58 158) Resolution: 1mV; 0.11(0.2) Accuracy: 5mV; 1(2) Operating Temperature: 0 50 (32F 122F) Battery: 41.5V(AG-13) Button Cell Battery (not included) Color: Yellow Material: ABS Item Size: 14.7 * 2.7 * 1.8cm / 5.8 * 1.1 * 0.7in Item Weight: 74.5g / 2.6oz Package Size: 21 * 10.4 * 5cm / 8.3 * 4.1 * 1.9in Package Weight: 157g / 5.5oz Package List: 1 * ORP Meter (Battery is not included) 1 * User Manual 1 * Mini Screwdriver