You will need to remove your valve core to get all the air out of a tube or a tool if you need to replace the valve. What's a better place to carry that tool but on your valve cap. There are two in this pack - one for each wheel. The cap also has a decent rubber seal to ensure crap wont get into your valve and will stop any minor valve leaks. Free freight with any other product that attracts postage or $5.00 on their own.