American-made light-filtering glasses for burner work These are light protection glasses for air burner work, made by Phillips Safety Products in the USA. The PH202 filter used in these glasses cuts harmful ultraviolet and infrared light. In addition to this, it also adjusts the transmittance of the yellow flame (around 580nm) produced during glasswork, as well as the blue, green, and red parts of the spectrum, so that the color balance of the original material is maintained even when viewed through the glasses. Box has some stains. #Glasswork #Lampwork #Phillips #LightFilteringGlasses