A superior side fixation part and inferior side fixation part mounted in the center portion behind the outer casing, have butthole for mounting the turning axis.
固定在外壳后方中心部位的上侧固定部件及下侧固定部件，其具有组装上述旋转轴的铰链孔；
2
Butt one day, a cigarette falls on it and makes a hole in it.