The invention provides a module being connectable to a mating connector having a tube and including a case and a connector. The case has a through hole that is larger than the tube so as to receive the tube. The connector fits into the tube along a first direction and includes a tuboid shell that includes a lip, first to fourth corners, and guides. The first and second corners are provided where the distal face of the lip meets outer faces on one and the other sides, respectively, of a second direction of the lip. The third and fourth corners are provided where the distal face of the lip meets outer faces on one and the other sides, respectively, of a third direction of the lip. The guides, each at least one of a chamfer, a rounded face, and a curved portion curved inward of the connector, are provided at the respective first to fourth corners.