The Fitwatch 10S is the smallest strapless heart rate monitor currently available and has the fastest heart rate pickup. The 10S offers top-of-the line features such as a calorie counter, high and low target zone alarms, audible and visual alarms, male and female settings, stopwatch and countdown timers and more. The 10S is water resistant and made from durable plastic. Its compact size and shape is designed to provide you with comfort while you train. Blue version also available.