"Comprises molded parts consisting of 30% glass-filled nylon, filter material as acrylic heat-resistant plastic according to MIL-P-21105 or MIL-P-5425. The filter color is translucent white, and the legend material is transparent, heat-resistant acrylic based on MIL-P-21105 or MIL-P-5425. The window material consists of high-temperature transparent self-extinguishing polycarbonate. Style B applies, with the legend type being IB. A bypass mode requires photo-etching or engraving at 0.090 in. H, 0.0151 in. P, and 0.003 in. line width in the area for legend type IB."