A light source with an integral surface of revolution to project an emergency warning light signal for a vehicle in a substantially horizontal 360\xb0 arc. A small or large drop waveform applied to a drop forming mechanism causes the liquid stream to break up into a small or large volume drop, respectively. By such arrangements, the multi-size wrench is applicable to a Metric hexagonal fastener, an English hexagonal fastener and a torx fastener which are correspondingly sized. The ring is preferably capable of swiveling within the borehole to allow the bone screw to be angulated at a plurality of angles oblique to the plate. 001 to 10 parts by weight of a metal complex having a monodentate or a bidentate ligand; and at least one metal andor its salt selected from the group consisting of copper, zinc, nickel, manganese, cobalt, chromium and tin.