M.S.
I've never heard of a removable palate expander. I had a permanent one as a teenager and personally think that a removable one would be a bad idea. It hurts a lot when you expand it and you'd be awfully tempted to take it out to give yourself a break and end up setting yourself back. Usually they don't give palate expanders to adults because you're bone won't fill in that space. They do surgery.