15:34 - I'm not an Expert on Door Closers But my Best Guess is that FP Mean Fire Proof or Fire Protected? I'm not sure but I think it has something to do with fire especially when the FP is Red and usually stuff that is red is a indicator for Fire related Stuff.
LCN makes great closers. LCN is all I use. I even have an LCN 4040XP closer on my garage entry door at my house. LCN is the only company that I use for closers. They make great closers.