Whats this for?

I bought a Mark Levinson 326S here and was looking over the owners manual box contents and I read "1/8-inch hex key". What the heck would an allen key come with a preamp for? While I don’t have the preamp in possession right now to look at screws. Would Madrigal/Harmon want you to remove the bottom of the unit for some reason, what reason? Or is it the feet that you can change?
Remote was an idea I hadn't thought of but I see it has Phillips screws on battery compartment.
The Hex key wasn't included with the white glove/owners manual pack so maybe Mark Levison is behind on up dating their "contents in box"?

2020matters OP

You might have dip switches inside to set your max gain for the volume control.

Cheers George
I've heard that some equipment makers will "float" the PC board on springs to isolate from external vibration. They are secured for transport with a screw that must be released once received. This is especially true for CD players but can see it on pre-amps, etc. Look for a hole on bottom of unit or read instruction book.
My Belles Aria integrated has a tiny screw that fastens the volume knob to the thing-y that turns (sorry for the lack of precision). It is tightened by a tiny key. 
I did an owners Manual search and only found Hex key in "box contents". I've attempted to mail Levinson already and its been a week and no reply. So, not sure that worked out, I'll try again.