For CT MINI and CT MIDI units manufactured from 2019 onwards as well as CT 15 Designed to trap particles down to .3 microns while maintaining airflow, allowing you to reach full capacity without clogging or caking. There is no better filtration on the market today. Includes 1 HEPA Filter Elements. -Quick and clean filter replacement: Easy replacement of filter cartridge from outside without opening the mobile dust extractor -main filter surrounded by practical plastic frame -easy replacement of filter cartridge from outside without opening the mobile dust extractor