This palm-sized pump packs a huge punch in a small package--it's dual piston design adds versatility. Works on both Presta and Schraeder valves at the switch of a lever. Dual piston design pump let you switch from high volume for quick filling, or low volume for higher pressure - all at the switch of a lever. Fully serviceable pump is great for mountain or road bikes, and pumps to 100 PSI. Made of lightweight fiber reinforced polymer for durability. Stores conveniently in a pocket for easy access.