Designed for Fat and Semi Fat tire bikes, the Air Tool Big Bore Pump packs massive volume-per-stroke, and it features a head that still works with winter gloves on to make it perfect for backcountry winter fat biking. Oversized press-on Schrader and Presta head won&';t accidentally remove valve cores and can be easily used with thick gloves. Flexible hose attachment allows for aggressive pumping without fear of damaging valve stems. Inverted barrel design allows for high volume in a compact size. Coarse machined aluminum barrel for extra grip. Water bottle boss mount with elastomer band included. Max pressure: 50 PSI (3.5bar) Volume-per-stroke: 90cc