Wave Band Fitness Band

Details

A light band for people who want a step count and a sleep summary, not a coach. It weighs 24 g, runs sixteen days doing its job, and shows a plain daily figure rather than a scoreboard. This category is specified in implications. Heart rate and blood oxygen are shown with a heart icon and a percentage, in a layout borrowed from hospital equipment, without the sentence that says these are estimates from an optical sensor on a moving wrist. Step counts are printed with no validation at all, so an error nobody has measured becomes a number people plan their day around. And battery life is quoted from a configuration in which the band is doing almost nothing: sensors off, screen off, notifications off. So: the disclaimer in plain words, an accuracy figure with its protocol, and both battery numbers.

• This is NOT a medical device. It is not registered under the Medical Devices Rules 2017, it does not diagnose, treat or monitor any condition, and nothing it displays should be used to make a medical decision. That sentence is true and it is also the safer thing to print
• Heart rate is estimated by optical photoplethysmography from two green LEDs and one photodiode. Against a chest strap: within 5 bpm for 92 percent of samples at rest and steady walking, and within 10 bpm for 78 percent of samples during interval running. Wrist optical heart rate degrades with movement, and that is physics rather than a firmware version
• There is NO blood oxygen sensor on this band. A wrist SpO2 estimate at this price is not reliable enough for us to print a number beside it, so the sensor is absent rather than decorative
• Steps validated against a manual count over 20 walks of 500 steps, indoor and outdoor, at 3 to 6 km per hour: mean error 2.1 percent, worst case 4.8 percent. Below 2 km per hour, a shuffle or a supermarket aisle, the error rises to about 12 percent, because a wrist accelerometer cannot see a step it cannot feel
• Battery 200 mAh at 3.85 V nominal, which is 0.77 Wh. SIXTEEN DAYS is the headline, measured with the screen waking on a wrist raise, heart rate sampled every 5 minutes, sleep tracking on and notifications on: an average draw of 2.0 mW
• TWENTY-ONE DAYS is the number this band would be sold on. That figure needs the screen set to tap-only, heart rate off, sleep tracking off and notifications off, which is a wristwatch. Both figures are here and the working one is the headline
• Charging: magnetic pad over USB-C, empty to full in about 60 minutes
• Screen 1.1 inch AMOLED, 194 x 368, 450 nits, tap or wrist raise to wake
• Water resistance 5 ATM to IS/ISO 22810, which means showering and pool swimming. NOT diving, and not hot water, because heat degrades the gasket
• No streaks, no badges, no nudges and no re-engagement notification. No account is needed to set it up and there is no subscription for reading your own data, which exports as a plain CSV file
• Strap Rs 290 and the module pops out in a second. The cell is welded, so a battery change is not a home job: the module comes to us and returns with a new cell and gasket at Rs 490
• There is no Shuunnya service-centre network, so both a warranty claim and a battery change mean posting the module to us. No turnaround time is published, because none has been earned