Wireless Cycle computer with wireless heart rate monitor Speedometer with digital display and image display Clock: 12/24H format option Speed comparator Average speed Maximum speed Wireless pulse measuring via the transmitter beltRelative speed Riding time Riding distance/total riding distance Thermometer Metric system and imperial system option Scan Sensing distance: 0.9m (35.4 inches) Battery:    1pc A23-12V for transmitter 1pc CR2032 for receiverSize: 59 x 58 x 16.8mm The sensor frequency for detecting speed is 125kHz It apply E23A/MA21-V23. 12 V battery, which will last for 1 and half year if used 3 hours per day

bicycle computer