We find ourselves in an internal debate between the Blackburn AirStik 2Stage and the AirStik SL -- faster pumping or smaller size. If you need it on your bike for a race, do you want to save 26g or have almost twice the air volume per stroke We go back and forth, but the greater air volume does seem worth the trade-off. The AirStik 2Stage can deliver 3. 5 cubic inches of air per stroke, which exceeds most other pumps that offer two different volumes per stroke. If you're not familiar with these, you should be. There is a switch on the pump, in this case on the bottom of the handle, which allows you to choose "high volume" or "high pressure." The latter is a polite way to say "low volume" -- something you will want as the pressure in the tire gets to a certain point as it makes the pumping easier. While the 2Stage is bigger than the SL, it's still pretty small. It is 172mm long when closed and has a 98mm long pump stroke. The barrel and shaft are aluminum. One of the things we like about this pump is that Blackburn hired a suspension fork engineer to work on their pump line. The result is mini-pumps that use the shaft space as an air chamber, which makes the pump action more stable and delivers more air per stroke. The Blackburn AirStik 2Stage comes with a mount that fits under a bottle cage. The head is designed for Presta valves only. Maximum pressure possible with the pump is 160psi. While this may not be important to you, Blackburn has made the pump so it can be rebuilt rather than tossed if a part breaks.