I have used the chrome screw-on valve extenders, but they came loose in travel because centrifugal force caused them to become unscrewed--just enough to let the air escape. That caused a flat tire. Since then I got the flexible extension hoses, about 10 to 12 inches long, and had them installed by an RV mechanic. They are attached with rivets to the hub of the wheel cover, so they can't cause a leak as the wheels turn. Seems to be working great! Makes it very easy to check tire pressure.