The Specialized Air Tool MTB Pump is our most dependable and durable big-volume frame pump. It's intended to be carried on the bike for use in all off-road conditions. You'll find that it features a new inverted design, so it greatly increases air capacity, which reduces pump time by up to two minutes. Specialized Air Tool MTB Pump Features All new inverted, double chamber design increases the air handling capacity by 28% compared to our previous design, reducing pumping time by up to two minutes. Twist locking head reduces size and can be easily converted to fit Presta or Schrader valves. Machined outer barrel for extra grip while pumping.. All-aluminium inner and outer chamber for durable performance. Water bottle boss mount included. Max pressure: 60 PSI (4.1bar) Volume-per-stroke: 100cc