Hi! Funny I come here for this instead of somewhere else haha Anyway, I'm trying to instal a GFCI breaker into my Murray panel for my reef tank I'm setting up.... (tank covers the electric outlet). I bought a Murray GFCI breaker, as hard as it was to find and everyone was telling me to just put a Simmions in there. So I take out the old one, hook up the load neutral and load to the breaker, and the pigtail to the neutral bar in the panel, only to find this thing does not want to snap in there. The door says 3 styles including MP which is what the breaker I bought is but it is a different pivot side and just doesn't work. Can someone explain to my why?