Ordered two. One was in perfect condition, but the other was not breathing. I removed the inner core valve and felt with an allen wrench to determine that the valve was blocked by something hard. Thought the blockage could be dried glue and punctured, being careful not to drill through the pipe walls or round off the internal threads of the valve stem. This fixed it. Now it works perfectly and no need to return it. Otherwise I would have given 5 stars.