Denver BFH-19 Waterproof Fitness Activity Tracker with Heart Rate, Bluetooth 4.0 - IP67 Improve your training or other daily activities with the versatile multi-functional fitness band Denver BFH-19. Track your activity, steps, calories calculation, heart rate, body temperature, or even sleep state. It has an IP67 waterproof certification, so you can use it while swimming. Pair it with a smartphone via Bluetooth, and you can receive SMS notifications or caller ID on display.