Kinetic by Kurt Wired Power Computer Computer designed to give accurate power readings, measured in watts, when using Kinetic Trainer (sold separately) All other functions are accurate whether riding a bike or working out on the trainer, making it a versatile cycle computer option Wattage determined based on mathematical relationship between power and speed; "Kinetic Power Formula," along with proprietary software, determines cumulative effect of 16 interactive forces Includes Wired Power Computer, stem/handlebar mount, speed transmitter with magnet, cadence transmitter with magnet, battery, and cable ties Includes limited lifetime manufacturer's warranty