Half air compressor - Half pump. The JoeBlow Booster pump just made it easier to install tubeless tires. This pump has an integrated aluminum air chamber that stores an air charge of one liter, up to 160psi / 11 bar, to quickly fill your tire and ensure the proper installation on a tubeless rim, just like a shop compressor. Once you flip the selector from CHARGE to INFLATE mode, air bypasses the chamber and flows directly into your tire like a standard pump. The top-mounted easy to read gauge, air release button and comfortable dual density polymer grip, combined with its extra-long hose and stable base makes mounting tubeless and standard tires a breeze!