What's an acceptable replacement for this? I don't see any Homeywell
4064E's anywhere. Mostly 4064B's or some other letter not E.
It's just a fan limit switch for an old gas furnace with an 11.5" shaft that goes into the furnace. I suspect that the replacement model number is different because I doubt anyone would really want an exact replacement because of the crappy push in electrical terminals on the one that I have. My guess is that any generic one that has the 11 shaft and is adjustable would work, but would like to confirm here.