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 60.0°C (32.0 to 140°F) Temperature Resolution: 0.1°C / 0.1°F Temperature Accuracy: ±0.5°C Working Environment: 0 to 60°C (32.0 to 140°F), RH ≤90% Waterproof Rating: 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 Backlight Temperature Compensation: Automatic from 0 to 60°C Data Retention: Automatic Value Hold Auto Power Off: After 5 Minutes of Inactivity H2 Calibration Point: 224ppb, ±20ppb Tolerance Application: Suitable for Swimming Pool Testing, Hydroponics, Aquariums, Gardening, Laboratories, Drinking Water Purification, Ponds, and Other Water Quality Testing Applications Weight: Approx. 139g / 4.9oz Package List 1 x Hydrogen Test Pen (Battery Not Included) 1 x User Manual