Im passing this info along from some friends who have used the new "stealth" gear. On the site it says no need to filter like bulk oils, completely sterile, blah blah blah. People who have not filtered it have ended up with a big nice red lump on there ass, infections, extreme pain. People who have filtered have had no problems that ive heard of yet. So if you decide to run stealth gear make sure to take the time to filter it thru a .2 whataman and expect it to take forever. just a heads up..