Features: Measuring range: 0-4000ppb or 0-4.000ppm, resolution 1ppb or 0.001ppm. High precision hydrogen meter with high sensitivity probe. with backlight, data hold function. Easy to operate,carry. Easy to change electrode. ATC symbol indicates that the instrument is in automatic temperature compensation mode. IP67 is an international waterproof and dustproof certification. for Protection against dust intrusion, short-time immersion. for Ideal for testing water, swimming pools, aquariums, spas, hydroponics, laboratory, and drinking water, etc. Specifications: Material: ABS Size: 183x37mm or 7.2x1.46in Button battery: included Note: Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Hydrogen Meter Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-YJL official store