CatEye Strada Digital Wireless Bicycle Computer w/Speed/Heart Rate - CC-RD420DW Digital speed and heart rate sensors are virtually interference free Current average and max speed Trip distance and total distance Detachable fabric hr sensor is more comfortable than traditional chest straps Upgradeable to triple wireless with digital speed/Cadence sensor 2.4Ghz Digital Wireless / Speed + Heart Rate (+ Cadence) 9 Functions & 10 Features PROGRAMMABLE DISPLAY - Displays SPD or HR constantly on top (CDC is also available with optional ISCTec sensor) Strada Speed/Heart Rate Double Wireless with the same 2.4GHz wireless technology of the V series