VDO Z-Series Cycling Computer Wireless Cadence Kit Wireless cadence kit will enable cadence for all Z series models and also provide data that gives power measurement in Z1, Z3 and Z3PC Uses cutting edge industry standard Ant + Sport protocol 2.4 Ghz digital signal to keep speed transmitter and other rider signals completely separate Discreet and clean design mounts to chain stay, downtube or seat tube Comes with zip ties and 3 V battery 5 Year warranty