details on the power computor?
What data it provides and
how/where it's installed?
You attach the actual readout to your handlebar similar to a outdoor bike speed-0/computor. Then you attach a small magnet to a spoke on the rear wheel of your bike (simple, using a screw driver) and attach a the "pick-up" sensor on the down-tube running from the seat to the rear axle. The sensor must be about 1 to 2 mm away (about the thickness of butter knife blade). The sensor is attached with simple "zip" ties (platic pull/lock straps). The only tool you'll need is a screw driver, everything else is supplied.
The readout gives you current bike speed, average speed for the workout, workout time, current watts (power), average watts for the workout, distance. To calibrate it to your bike, you need to enter the tire diameter, but the instructions are pretty clear on how to go about this. Go the the KK site and click on the "Accesories" tab for all the features.
You could probably leave it on your bike when you ride outside as a speedo/odo etc. But I'm not sure how waterproof it is. I have a speedo attached to my front wheel so I'll take the KK unit off when I get ready to ride outside - I'm in Ohio
If I were to do it again, I'd just move my old speedo/comp to the rear wheel and use that. I could measure power indirectly by monitoring speed. But if you don't have anyway of measuring your speed I recommend it. I paid about $50 from BicycleBuys.com