World's Largest Round Vault Door

[timelocks]

I've been asked to comment on this photo, It's quite poor but it could be a quad N as someone has suggested, but the surrounding vault door looks way too small to support this type of lock, could it not be a quad L? Either way, as Mercury noted, it is exceeding rare to see a quad for an automatic bolt motor. After reading this thread I realized I had mistaken my ID for the Yale quad originally called a Quad L but is a Quad K as the Yale literature states. Thanks. Please let me know other mistakes you find. I want he web site to be as accurate a reference resource as possible.

An amendment, I did not realize the photo was a segment of a door, again a poor photo, but I now see it is from the Cleveland Fd.so yeas I'm sure i's a triple M.