LEMFO LF21 Smart Watch: Perfect combination of tradition & smart technology, with new watch needles design, LF21 shows more charm. Compatible with Android 4.3 or above, IOS 7.0 or Above, Bluetooth 4.0 or above. Alloy Case with Silicone Strap: Exquisite appearance & quality made by precision mold. Professional Waterproof: Water resistant 5 atm or 50 meters. Suitable for swimming white water rafting, non-snorkeling water related work & fishing. Sport Monitoring: 24 hours activity tracking, accurate records of each action, including the movement distance, time, calories burned, activity, a complete record of your daily activities. Call Remind: Whenever there is an incoming call or message, you will be reminded on watch SMS & App remind. HDware: Model: LEMFO LF21 Bluetooth: BT 4.0 Display: FSTN/ full view Light: EL Cold light panel Sound: Ceramic buzzing Battery: CR2430 Sensor: BMA222E (3D) Compatible with Android 4.3 or above, IOS 7.0 or Above, Bluetooth 4.0 or above. Performs: Operating voltage: 3.0V BT Current: 0.25m A Step counting current: 0.025m A Sound current: 6 m A (Buzzer) Luminous current: 12 m A Standby current: 0.012 m A (All function turned off) Buzzer sound: 40-50 d B Luminous brightness: 5 LM RF band: 2379-2496 MHz Waterproof Level: 5 ATM Button life: 100k times