Yeah, they don't stand up to pressure much, do they? I took one with me to Home Depot to have in hand to fit some vinyl tubing around the inside (to use for blow-off tube if needed) plastic piece. Well, after sliding the correct sized tubing onto it, I couldn't get it back off! Ended up snapping the plastic inner piece right off, and then I still couldn't get it out of the tubing... D'oh! I've seen many people use that airlock with tubing set up for a blow off tube, but after that just decided to scrap that idea and skip the airlock part altogether...