In addition, although the lower wall of the second peripheral side-walls 57 is disposed at the lower side the lower wall of the first peripheral side-walls 55, the lower wall of the second peripheral side-walls 57 may be disposed at the upper side of the lower wall of the first peripheral side-walls 55.

In addition, in cases in which the leading end side of the second peripheral side-walls 57 overlaps with the leading end side of the first peripheral side-walls 55, the leading end side of the second peripheral side-walls 57 may be to the inside or to the outside of the leading end side of the first peripheral side-walls 55.

(3) Although the first casing body 52 and the second casing body 53 illustrated in FIG. 7, etc., preferably each have electromagnetic shielding properties, configuration may be such that the first casing body 52 and the second casing body 53 do not have electromagnetic shielding properties. In cases in which the first casing body 52 and the second casing body 53 do not have electromagnetic shielding properties, the cables 63 may be a shielded cables having electromagnetic shielding properties.

(4) As illustrated in FIG. 13, the first guide pins 66 are provided to the positioning pieces 65 and the first guide holes 33 are formed in the rim of the opening 31 of the housing section 30. However, the first guide pins 66 may be provided to the rim of the opening 31 and the first guide holes 33 may be formed in the positioning pieces 65.