The F4tm is the first womens specific unit from Polar, combining all the necessary heart rate features with a new, slim design. The F4tm includes the popular Zone Pointer feature that helps keep you in your Target Zone, and OwnCalr to track the calories you burn during your exercise. With stopwatch and convenient button free operation, the F4tm is a valuable fitness tool. Available in four color options. Black Thunder is the Mens version of the Polar F4. Polar exercise features b
)
