This Jobe Triple Action pump is designed to inflate your stand up paddle boards to a pressure of up to 21 PSI easily and quickly! It is made up of two 3.5 liter double action tubes, a pressure gauge and a Harlkey Roberts tip compatible with all Jobe boards (and others!). This pump has three operating modes to make inflation easy at every stage: double action on the 2 cylinders to inflate super fast up to 5 PSI. Single action on both cylinders to quickly rise to 10 PSI. Then simple action on a single cylinder to effortlessly rise to a pressure of 21 PSI. Essential, we tell you!