Ascent is one of Performance bike’s house brand. However they very similar to the Avocet company in that they seem to have pretty much disappeared. Even Performance does not seem to carry them any more. (although they did have replacement wiring harnesses , last time I checked).
I did find one small site that seems to have some Ascent reset instructions. In case their page gets deleted, I’ll post some of the highlights, here:
You can still find them for sale on eBay, and I see no reason why not to go for that. The setting instructions should be included in the packaging, and you can get them for an extremely affordable price.
One downside is that their wireless models seem to have a very finicky connection. One user even reported that he had to mount his computer sideways to get a good reading from the fork-mounted sensor.
So if you have a lot of accessories on your handlebars that you will need to work around, this will likely be a poor choice.
Unlike the old Avocet, you don’t find anyone bragging about theirs lasting for 20 years. So, I’d be inclined to hold onto my money and upgrade to something like the Cateye Velo 5.
But, if someone gives you one, thank them, and slap it on your bike. Might as well get all of the use out of it that you can!