The AmAir HT pleated filter is designed for conditions that require a UL Classified filter and for applications with continuous operating temperatures of up to 500˚F. AmAir HT is made with ultra-fine glass fibers formed into a high loft mat, increasing its dust-holding capacity. The frame is an aluminized steel U-channel, with the scrim-backed media pack bonded to the inside on all four edges. An expanded aluminized steel faceguard is spot welded inside the frame on the air leaving side to retain the media pack at elevated temperatures.