features click-fit design quickly installs into enclosure wall; no tools or screws required opens with the flick of a finger for easy filter replacement enclosure side wall mounting reverse airflow option on hf13 models available to push/pull air through higher static pressure standard rope gasket provides proper seal to the enclosure similar cut-out sizes as other filter fan manufacturers terminal block connections optional thermostat available to save energy and extend service life hinged grille remains attached after opening