The tracker is great for the price. It works well and corresponds to their functions (check steps, heart rate, sleep time, etc). Especially it can even control my camera& music player and notify me when calls and messages coming through. Pleasant buy and the fact that the seller checks up on u independently even better.

Specifications:
CPU: Nordic nRF51822
Sensor: kx022-1020
HR Sensor: Silicon labs Si1142
Standby Time: up to 5-7 days
Display Screen:0.49'' OLED
Battery:70mAh rechargeable Li-polymer battery
Data Sync: Bluetooth 4.0
Strap Size :260x21x12.5mm
Weight:51g
Bluetooth Working Range: up to 10m
Waterproof: IP67
Requirement: iOS 7.1 or above; Android 4.4 or above, Bluetooth 4.0

Common problem:
Q1:Is this waterproof? Can i wear it to swim?
A1:It's IP67 waterproof.It is suitable for Sweat proof, rain proof, water drop proof.Wear it to swim diving or shower may do harm to its battery
and lead to a failure waking-up device.

Q2:Can I use the tracker to text or make a call?
A2: No, but it can show the incoming call and other app notification, but it can't display information content.

Q3:Can this tracker work alone?
A3: Yes,the bracelet can record steps, Calories, heart rate .it can't use other function and save data if you can't pair your phone.

• 【Multi Functions】Heart Rate Monitor, Pedometer, Calories Measure, Distance, Sleep Monitor, Call Reminder, Alarm Reminder, Anti-lost.
• 【Remote Camera Control】Device key could control remote photograph shooting.
• 【Heart Rate Monitor】1. click to heart rate menu, and the heart rate inductor's green light on the back of the band is on. 2. Close the back of the band, the inductor to the muscle. 3. Read the number after 10 seconds. If it is not done in this way, the measure of HEART RATE maybe not correct. (Please note the heart rate data is for your reference, NOT for medical use).
• 【Technical Design】0.49" OLED screen will automatically light up when you turn over hand, 5.5" - 7.6" adjustable silicon band fit for different wrist size, IP65 daily waterproof design.Compatible with Android 4.4 or above, iOS 7.1 or above,Bluetooth 4.0 or above.
• 【Remind Alerts】Alarm alert, call alert, sedentary alert,etc.by silent vibration.【Anti-Lost】When the smart phone is beyond the Bluetooth range (no more than 5m), the device vibrates to remind.

【Multi Functions】Heart Rate Monitor, Pedometer, Calories Measure, Distance, Sleep Monitor, Call Reminder, Alarm Reminder, Anti-lost.REDGO