One thing to add for the original poster. If you just leave everything about the install to the shop at least read the instructions manual concerning programming the gears. As others have said, it is a little bit more involved than with other computers and the manuals are to some people not as forthcoming so it might take you a bit to understand how to do it. If you can't figure it out from the manual, you might want to have the LBS walk you through a programming procedure. Whenever you replace the batteries, you will need to reprogram the thing and you probably don't want to have to take it back to the shop each time to have it done.