Now I remember why I go out to the ISS so infrequently, whata PITA... Can't count how many needles I've got stuck in me. Anyway, after about a 16 month hiatus, I can report that the SF2 did it's job, I literally could barely see the filter as it was completely encased in dust/dirt. No matter, it still worked, and well. Can't recommend this enough, especially for people like me. Also stuck in a new 31, although the old one was fine. Lets see how that goes.