Careful though. Those things can destroy your hvac system, which is not designed to deal with a severe restriction like that. Plus, they won’t last long with no

Careful though. Those things can destroy your hvac system, which is not designed to deal with a severe restriction like that. Plus, they won’t last long with no pre-filtering at all. Shame to have a great filter like that just clog up with hair and pollen in three weeks.