A connector that includes: a box-shaped substrate side housing containing a terminal mount wall extending in a plane defined by mutually orthogonal X and Y axes, four side walls; and terminals arranged in two rows, the rows being apart from each other in an X axis direction, such that the terminals in each row are in alignment with one another in a Y axis direction, is provided. A lock part is provided on one of the two first side walls for detachably locking a plug housing in an inserted position, and, on each of the second side walls, a first and a second reinforcement plate mount parts are provided at two different positions apart from each other in the X-axis direction, and a reinforcement plate may be mounted to each of the two first and the two second reinforcement plate mount parts. The housing may be alternatively mounted in an upward opening manner or in a right angle manner and with the reinforcement plate edges soldered to a printed circuit board in each case.