Merv 8 Pleated Air Filter - 16 1/4" x 21 1/4" x 1" Quantity:12-pack if not you can measure

if not you can measure it or check the HVAC unit and the owner‰۪s manual

such as dust

these can be purchased in any conceivable size

Kills bacteria

Merv 8 Pleated Air Filter - 16 1/4" x 21 1/4" x 1" Quantity:12-pack if not you can measureAny Kind of Filter's Extended Surface Pleated Filters outperform ordinary furnace filters with medium efficiency and are designed for lower pressure drop, and long service life which reduces HVAC equipment maintenance and energy costs. A higher MERV rating means that the air filter that you are about to purchase possesses a higher amount impurity filtration ability than your ordinary filter.