Sunlite no Power Bicycle Computers
About Sunlite - "Every year bikes change, styles and trends evolve, old bikes are in need of repairs and new bikes are waiting for that personal touch. We provide the means to keep your bike on the road and fun to ride!"
Some cycling computers can display a power reading, usually in watts. They usually require a separate sensor - in some cases a special hub or crank arm. A few will estimate the value based on speed, cadence, rider weight or other data. "Optional" means it can read from a separate power meter or sensor. "Included" means it is calculated by the computer or includes the neccessary sensor.