AC22/AC21 is a twin motors Auto pulsing HEPA dust extractor.It is the most popular model for the medium size concrete floor grinders. The 2 commercial grade Ameterk motors provide 258cfm and 100 inch water lift.Operators can controll the motors independently when different power is wanted. It featured with Bersi innovative Auto pulsing technology,which solve the pain of frequently stop to pulse or manually clean the filters ,allows the operator 100% uninterrupted working, labor saving greatly. When fine dust is inhaled into the lungs, it is extremly harm to the body, this vacuum build with high standard 2- stage HEPA filtration system.The first stage equipped with two cylindrical filters rotated self cleaning.When one filter is cleaning, the other is keep vacuuming, you don’t have to worry about the clogging any more.The second stage has 2pcs H13 HEPA filter individually tested and certified with EN1822-1 and IEST RP CC001.6 standard.This high-performing unit meets OSHA’s dust collector requirements and helps provide a cleaner, healthier work site. Like all Bersi cassettes dust collecctor, AC22/AC21 equipped with continuous drop-down dust collection into a plastic bag or Longopac bagging system so you can enjoy mess-free dustless disposal. It comes along with 7.5m*D50 hose, S wand and floor tools.This ultra-portable dust collector easily moves around congested floor and loads easily into a van or truck when transport.