Where I down load a instruction sheet for the computer. thanks

Trek's web site, under "Equipment and Accessories" has discriptions of all of their cyclometers and each one has a tab for Instruction Manual. See if you can find yours or one like it. I think Trek's are made by Cat-Eye (the earlier ones were) so their web site is another possibility.

None on that site worked for my old computer, I think trek bought them from Gary Fisher. It may be just too old to find anything, other than a biker who may have one on hand to scan.

Check out Sheldon Brown's web site. He has several articles on cyclometer installation and calibration numbers for many models. Here is the index to the various articles:

https://www.sheldonbrown.com/cyclecomputers/index.html

Been there too, it was close but not exact, thanks for the replys.

Did you find it ?
Thanks
Alberto

I have an old Trek Sensor 2 button, like to the picture posted by gonogo and need an instruction manual. Thank you. Alberto