A first housing is a grooved recess that stretches in the longitudinal direction, with a protrusion of a second housing inserted into the recess, a first terminal includes a mating terminal housing part mating with a second terminal, with at least a portion of the first terminal embedded in the first housing and integrated with the first housing, and the mating terminal housing part includes a pair of contact protrusions protruding towards the center in the width direction of the first housing, with at least each contact protrusion exposed from each of a pair of side faces of the recess.