Abstract: A third back-up light for vehicles is disclosed. A back-up indicating light of the present invention is disposed on corners or lateral area of a rear lamp set, and works synchronously with the original back-up light so as to enhance insufficient warning effect of the original back-up light of the rear lamp set as well as increase visible angle or warning area of the back-up light. Moreover, the third back-up light is integrated with the rear lamp set without influence on original function of the rear lamp set. Thus the assembling of the present invention is finished at the same time with the assembling of the rear lamp set so as to become a general specification for the rear lamp set. Furthermore, the third back up light can emit white light, light with other colors, or blinking light, all achieve the warning effect.

Abstract: A retractable support arm structure, which includes an upright tube fastened to a base, an telescopic arm, which has a bottom end downwardly inserted into the upright tube and a top end connected to a steering mechanism holding a load such as LCD monitor (or LCD TV), a first friction member capped on the top end of the upright tube and disposed to contact with the periphery of the telescopic arm, a second friction member capped on the bottom end of the telescopic arm and disposed in contact with the inside wall of the upright tube, and a spring member, which is mounted inside the upright tube, having a top fastened to the upright tube and a bottom end coiled up to form a helical spring portion that is to stop against the second friction member.

Abstract: A pneumatic tool accessory is provided in a body thereof with a stress monitoring structure comprising a stress intensity control portion serving as a breaking point of the body, and a stress intensity monitor formed of a reference mark and an indicator mark. The indicator mark and the reference mark are separated from each other by the stress intensity control portion such that the indicator mark is aligned with the reference mark, and that the indicator mark is nonaligned with the reference mark at such time when the stress intensity control portion is deformed by a straining force exerting on the body.