An abutting portion is provided as a portion of an edge portion of an upper wall portion, and abuts against an edge portion of a first side wall portion when the upper wall portion bends toward the inside of a tubular wall portion. The projection portion projects from the upper wall portion, and restricts insertion of the tubular wall portion toward the back of the housing by abutting against the housing when the tubular wall portion is inserted into the housing in an orientation different from a predetermined insertion orientation. The engaging portion is configured to be able to engage with an engaged portion provided on an inner side of the housing. The engaging portion is provided on the tubular wall portion at a position that shifted from or separated from the projection portion in the longitudinal direction of the tubular wall portion.