New to this!

[Robbiewhyte1976]

Can someone please explain the operation and mode button on the shifters (qs ultra 10) of my 2009 mono q
thanks in advance!

[KGB]

It's for the Campagnolo Ergobrain integrated computer. Basically a bike computer that could tel you what gear you were in and be controlled from the hoods. Possibly calculated your cadence as well, based on speed and gear ratio.
It wasn't overly popular and when gps computers came out it was the nail in the coffin.

Google will have more details if youre still keen to know more.