This product functions well. It was simple to pair with my phone, and I successfully used it with both the Adidas Running and Strava applications. My heart rate readings were generally consistent with my Samsung Galaxy Watch 3 while running, with occasional discrepancies of 2 or 3 beats, suggesting accurate calibration. Delivery was swift. I'm a repeat customer, having owned a previous one from this brand (lost 2 years prior). Thanks!