I got ambitious today and attempted to yank the blower motor housing out of
the car to replace the thermal fuse we talked about earlier.

Do you happen to know what kind/size the bolt on the upper left hand side
is?  I can't see up there and it is a mother trying to fit different hex
keys in there.  I hate buying a bunch of separate hex keys just to find the
right one.  That is, if it is a hex head nut. ( I need to get a dentist's
mirror)

This is a US Focus by the way if it makes a difference.

Thanks again.