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Device for adjustment of the position of the filament of a light bulb; and an optical instrument to adjust the position of the filament of a light bulb at the focus of a concave reflector.In an installation of light sinalizacao
Device for adjustment of the position of the filament of a light bulb; and an optical instrument to adjust the position of the filament of a light bulb at the focus of a concave reflector.In an installation of light sinalizacao
