CM4 if this is the carrier board you are referring to, the CM4 module, needs to be plugged into a carrier board, either a Raspberry Dev Board, or other third party dev boards, or the Turing Pi carrier board, which then needs to be plugged into the "edge socket", unlike Turing RK1 and Nvidia Nano which can plug straight into that socket, I hope that answers your question, if not post back and we can expand.