1. Lightweight and portable, Accurately measure water and protect the health of drinking water for the entire family. 2. Multi function switching at will 3. Dust and splash proof design: Comply with IP67 waterproof grade 4. Adopting a large LCD backlight screen for clear and easy reading 5. Built in highly sensitive electrode head, using highly sensitive glass electrodes and rust resistant platinum electrodes With Backlight Or Not:YES Display Type:DIGITAL Product Name: 7-in-1 Water Quality Testing Pen Measurement range: PH/ORP/EC/TEMP/SALT/S.G/TDS Automatic shutdown: 5 minutes Battery:3 x 1.5V LR44 Button Battery (Not Included) Product measurement range: 1. EC: Range: 0-10000us/cm, 10.01- 19.99mS/cm, 20.1400.0mS/cm (Convert range automaticly) Resolution: 1uS/cm; 0.1mS/CM; Accuracy: ±2% F.S. 2. TDS: Range: 0-10000ppm, 10.1- 200.0ppt (Convert sangeautomaticly) Resolution: 1ppm; 0.1ppt Accuracy: ±2% F.S. 3. Salinity: Range: 0.01%-25.00% Resolution:0.01% Accuracy: 0.01-5.00% (±0.1%); 5.1-25.0% (±1%) 4. pH: Range: 0.01-14.00рH Resolution: 0.01pH Accuracy: ±0.05 pH 5. ORP: Range: 0-±999mV Resolution: 1mv Accuracy:±2mv 6. S.G: 1.000-1.222 Working environment: 0 to 60.0℃(32.0-140℉); RH 100% 7. Temperature: range: 0-60℃ (32-140℉) accuracy: ±0.5℃ resolution: 0.1 ℃/℉ Colour:White & Blue Material:Plastic + Metal Package Contents: 1 x Water Quality Tester Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.