NORTH EDGE Men Dive Sports Digital watch Mens Watches Military Army Luxury Full Steel Business Waterproof 100m Altimeter Compass We Ship via ePacket (China EMS) to US and some other European countries So the product will take a short time to be delivered 0. Dive Mode (Dive depth, Max dive depth 50m, water temperature) 1. Waterproof 100m 2. Altimeter 3. Barometer (48 hours air pressure trend chart) 4. Compass 5. Thermometer (Temperature) 6. Pedometer, step counter, calorie, distance record 7. Time functions: hour, minute, second, year(2000-2099), month, date, weekday, 12H/24H format 9. Countdown timer (99:59:59~0) 10. Stopwatch (0~99:59:59), 50 sets of data 12. WorldTime functions (daylight saving time switch automatically) 13. Digital compass 14. Battery life remind 15. EL Backlight FAQ Q1. Why the temperature is incorrect? A1. when the watch worn on the arm, affecting by the human body haetm the temperature value display on the screen will be higher than room temperature. So if you want to get the room temperature, please put the watch on a table, and avoid direct sunlight on it, the actual room temperature will show on the watch after 20 minutes. Q2. How long can the watch battery use? A2. Can be used for 8-12 months. There are a big battery is CR2025 is the electronic screen battery, the small battery is SR626SW is the pointer battery. you can use one coin turn contrarotate back cover. Q3. Can the button work normally in the dive mode? A3. Can't, Considering diving safety, button are closed under diving mode. expect "light" buttom. Q4. What is the diameter of the screen protector glass? A4. Screen protector glss dia is 40mm. you can buy this link. https://www.aliexpress.com/store/product//1635007_32967909963.html?spm Special Function: No-fly time When you return to the water surface after diving, no-fly icons will display on the upper part of the screen in different modes. Note: when the diving depth arrives 10M or More, the diving time is 1 minute or more, the no-fly time interface and the no-fly icon will display. ?NOTE: Only the watch is in countdown no-flying time, don't fly. before fly, please check the surplus no-fly time frequently! If you want to fly or move to the higher altitude in the no-fly time, it will influence you body.