I just installed some 4" recessed cans in a remodeled bathroom and am
choosing bulbs.

The Halo trim kits say that the max bulb wattage is a 50 Watt PAR20 or
a 50 Watt R20.

So, I have a halogen bulb (an R20) that says "40 Watt = 75 Watt" which
appears to be saying that this halogen bulb uses 40 Watt of
electricity to produce light that is equivalent (in some sense) to a
75 Watt incandescent.

Question: is this R20 bulb ok for my 4" can? I think it is and in
fact is slightly undersized since the trim kit allows a 50 Watt R20
and my R20 is only 40 Watt. Is that right? I probably should just
ignore the incandescent comparison but I want to make sure.

Thanks,

mh