1. Space-saving: Maximum air volume per stroke of pump. Patented tube-in-tube opposing pumping structure gives maximum air volume per stroke. 2. Ergonomics and comfort: patented 2-stage high-volume or high-pressure setting fits all kinds of pumping needs and the user’s physical condition very easily. 3. User-friendly: patented auto-switching Schrader / Presta valve system provides the user with maximum flexibility at the pumping site, no more switching valve cap and rubber grommet or missing parts. 4. Rotating gauge housing provides user with a better viewing angle during pumping. 5. Simple and attractive design.