Mini Air Purifier 2 PcsEliminate Printing Odor: The built in battery driven motor pumps air to the activated carbon to absorb and filter the resin odor during the printing. Comes with 4pcs of Carbon Filters: 2pcs are in purifier and 2pcs are packaged individually. The same carbon block is not required for the separately purchased (you can even put in small pieces of activated carbon directly). Widely Applicable to Various Resin Printers: It is compatible with most LCD DLP