This bicycle pump keeps what it promises. One can without problems a bicycle alone inflate without a need to hold the top, while the other pumps. The solution, three different types of valves to be able to fill up with air without an adapter, is well thought along and implemented.
A small gripe with Amazon: The carton in which came the pump was about three times larger than necessary.
Otherwise: Recommended to anyone who wants to pump up their bike tires alone hassle free.
