Blackburn's Mammoth 2Stage has a massive barrel designed to quickly inflate mountain bike tires, and 2 pumping modes to make the job easy. Just push the button at the end of the handle to pick your mode. Low moves a lot of air per stroke for fat, low-pressure tires, while the high mode makes the pumping easier on higher-pressure rubber. This great mini boasts an aluminum barrel and Blackburn's TwistGrip III head that fits Presta and Schrader valves. Plus, it can be mounted next to your bottle cage with the included clips.