An optical recording medium includes a support substrate, and a light transmission layer 12 that is disposed so as to come in contact with the support substrate. The power amplifier apparatus and a power amplifier circuit thereof in the present invention improves the efficiency of the power amplifier. Additionally, the apparatus may contain a locking system for restraining the securing member in a secured orientation and an angled receiving area on the securing member suitable for forcing the received tab inward towards the chassis. Upon sufficient mechanical movement of the trigger device and the blocking member, the latch is no longer restricted by the retention surface. The stretching device further includes an elongated flexible member forming a loop and having a connector adapted for securing stretchable film.