Specification: 1. Measuring range : -20 ~ 50 (-4 ~ 122 ) 2. Temperature measurement accuracy: 1 3. Temperature resolution: 0.1 degree 4. Waterproof index: IPX3 ( 5. Food : 3.0 V, benefits in kind: a CR2032 button cell 6. Size : 89 * 60.5 * 24mm 7. Net weight : 44g (battery included) Key operation 1. Introduction to key functions (see left photo) 1) [CLR] key: Reset maximum and minimum temperature records. 2) button: turn on or off 3) [C / F] key: Press this key to switch between Fahrenheit temperature display and Celsius temperature display. [Large LCD Screen & Waterproof] - You can see the reading at a glance on the large, easy-to-read LCD screen. Good help for people with poor eyesight. IPX3 Waterproof - The waterproof structure keeps moisture out of the cooler or freezer and ensures it operates safely and consistently. [Record minimum and maximum temperatures] - It provides historical temperature readings. With this feature, you can easily monitor temperature changes in the refrigerator and protect your food safety in two ways.