The ft4 is an entry level heart rate monitor and replaces the ever popular f4 heart rate monitor it looks and works as a digital wrist watch with dual time zones date of the day and alarm features it also comes with a chest strap that measures your heart rate and transmits wirelessly it to the watch wear it when you go for a brisk walk jog or yoga session an alarm will sound if your heart rate falls outside the desired zone which is a balance between cardiac safety and an effective workou