Sealed enclosure air-to-air indoor cooling heat exchanger comes with unique counterflow aluminium core for high-efficiency and high-performance heat transfer. Streamlined aesthetics with no visible mounting rails; Slim design allows for mounting to narrow or shallow enclosures. Reliable top-quality bearing fans and impellers make these units run quietly and with increased reliability. Low-carbon mild-steel sheet-metal cover for rugged factory environments. Filterless design for low maintenance and easy cleaning.