Specification Item Type: Hydrogen Test Pen Material: ABS H2 Range: 0 to 2400ppb, 0 to 2.400ppm Resolution: 2ppb, 0.002ppm Accuracy: 10ppb, 0.01ppm Temperature Range: 0.1 to 60.0C, 32.0 to 140F Resolution: 0.1/0.1 Accuracy: 0.5C/F Working Environment: 0 to 60C (32.0 to 140F), RH 90% max Waterproof: IP67 Battery: 3 x 1.5V Button Battery (LR44) (Battery Not Included) Product Size: Approx. 183 x 37mm / 7.2 x 1.5in Display: LCD Digital Display with Backlit Temperature: Automatic Temperature Compensation 0 to 60C Data Retention: Value Retention Automatic Shutdown: After 5 Minutes H2 Calibration Point: 224ppb, 20ppb is within normal range Application: Suitable for swimming pool testing, hydroponics, aquariums, gardening, laboratories, drinking water purification, ponds, and other water quality applications Weight: Approx. 139g / 4.9oz Package List 1 x Hydrogen Test Pen (Battery Not Included) 1 x User Manual