Cool feature on Pass X260.8 Mono Amps

For the Pass Labs owners out there who are enjoying their Pass mono block amps, the back panel sports two sets of speaker terminals and two small round “windows/pods”. The two sets of speaker terminals are pretty self explanatory, but what are those two pods labeled L and M? This may be funny and stupid at the same time but I couldn’t figure it out - I purchased the amps used and a manual is nowhere to be found as well as the documentation online is generic and doesn’t talk about it.
Well finally, after an extensive google search I got to the post on one of the audio forums where I got my answer!

You can adjust the Light (L), and the bias meter needle (M) to match the two amps perfectly! It so happens that on my amps one meter had the needle right over letter P. A needle on the second amp rested just below the letter P. Using a small flathead screwdriver making a small adjustment on the M pod I was able to match the meters!

This may be stupid and everyone else knew about this, but I’m pretty excited about it and decided to share. Anyways, Happy Listening!!!