Okay, they may not save your LIFE, but they will probably save you an hour or two of hard work while the rest of your party waits and watches. Stick it in the hole. Tighten the nut. Fill it up with air. Ready. No jack. No wrench. The pearl is not broken. If I had one complaint, it was that half a dozen of the balls I bought ended up in my buddies' rigs. But I'd rather donate a $15 valve than spend two hours fighting a dirty 40-inch swamper or even sit and watch someone else do it.