Featuring both single and double action models. Use the double action mode to generate large volume of air at low pressure. When pumping becomes hard, switch to the single action mode to finish up inflation. Use the INF port to inflate and the DEF port to deflate your iSUP. INF port is located on the pump body instead of on the handle, to avoid the hose moving up and down during inflation. Traditionally located inside the pump body, the connecting tube is moved to the outside to lower friction and increase efficiency. As a result, it is remarkably light and easy to push down and pull up the handle when pumping. High accuracy pressure gauge on the pump body is easy to read during inflation. Recommended pressure is highlighted on the gauge. Reading up to 29 psi. The handle can also be disassembled to save space when packing up.