A handset device includes a housing and a battery cover mounted on the housing. The major component of the layers A1 and A2 is polyethylene terephthalate and the stress at 100% elongation in the film’s longitudinal direction and width direction at 150\xb0 C. With the rear surface joined to a support surface, a space part is formed between the insertion tip part and the opposite surface thereto on the support surface side. The second and third conduit apparatus of the kit are for selective mounting to the first conduit apparatus. Upon removal of the control voltage, the charge storage device is discharged through the main tripping coil so as to move the armature to the dropped-out position.