That little opaque one is the selection circle? It naturally appears on some units [mostly air?] all the time. Some units just don't have it. Both units marked selectable and unselectable can have it. .~ Is there a flag [or something else] to turn it on and off? Thank you all for your quick replies.
EDIT: I tried a quick look around and thought it was in the model somewhere. But I have two units using the same model and one has it and one doesn't.