Polar G1 GPS Speed/Distance Sensor

Pair your Polar heart rate monitor or training computer with the G1 GPS Speed/Distance Sensor to accurately measure your speed and distance during low-speed activities. Use this water-resistant sensor with the Polar RS200, RS400, S625X, and S725X units for activities that dont exceed 18.3 mph, such as running, kayaking, or cross-country skiing. This lightweight unit uses SIRF StarIII GPS technology to give you the most accurate data possible.