AstroCel I HT-500 filters are used in applications that require high levels of contamination control at operating temperatures of up to 500°F (260°C). The filter consists of water-proofed, fire-retardant fiberglass media formed into a series of pleats. Corrugated sheets of aluminum separate the pleats to permit maximum usage at minimum resistance. A filter frame made of aluminum or stainless steel encloses the media, which is sealed to the frame sides with a red RTV silicone bond. Gasketing is available on the upstream, downstream or both faces.