I've got a Yankee safelight that takes filters 4" in diameter I believe (not in front of me at the moment). They are different than the circular Kodak filters which are 5". I only have an amber and I need a dark red for ortho materials. If such a thing exists, let me know, and if you've got one, even better. ALTERNATIVELY, if you've got a red bulb that you want to sell, I'd take it.