Polar RCX5 TDF Premium Heart Rate Monitor (Yellow/Black) Provides heart rate even in water with the comfortable hybrid transmitter ZoneOptimizer coaches you to train at the right intensity Sport profiles guarantee a swift switch between different sports Includes G5 GPS sensor, CS speed sensor W.I.N.D. and the s3+ stride sensor for cycling and running speed, distance, pace measurement Light (46g) and always ready for use with no need for charging