Heart rate chest belt measures your heart rate and transmits the data to most compatible 5 kHz receiver devices. Comfortable soft chest belt is washable. Compatible Gymstick devices: CT-90, FTR 90, PRO BIKE 50, PRO CROSS 50, SB-FTR, ATTACK BIKE, RW-H2O, TM-RUN 2.0, TM-RUN3.0, TM-RUN4.0, TM-RUN7.0, TM-RUN10.0