I don't know if this has been posted before. The new units being produced are HEPA CERTIFIED. The older units are not. Festool is now offering a free update to make them compliant (filter and some HEPA stickers) . Just ordered mine today. Good luck
http://www.eparrphepavacuum.com/hepa-vacuums/EPA-RRP-Certified-HEPA-Vacuum/Free-Filter.aspx
http://www.eparrphepavacuum.com/hepa-vacuums/EPA-RRP-Certified-HEPA-Vacuum/Free-Filter.aspx