The new Hand compressor pump is a multiple inflating system pump that can act in two modes:
Mode 1 or HIGH CAPACITY mode, or a double action mode of 2.1+2.1 lts where you can inflate your board from 0 up to 18 PSI of pressure .
Mode 2 or HIGH PRESSURE mode or single action mode of 1,8 lts, where you can pump up to 29 PSI of pressure. (maximum inflating pressure on your board should be 18 PSI).
The mode 2 is recommended only for kids or lightweight girls in order to help inflating your board up to 18 PSI of pressure requiring less power on your arms.