This will make it easier!
SUP electric pump adaptor utilizes a standard Schrader valve fitting to couple with an air compressor or bike/tire pump.
How to use:
With the valve in the closed position, insert the Schrader valve fitting and rotate to lock in place. Remove the cap on the fitting, and connect a standard electric pump bike pump or compressor and inflate to the recommended PSI
Because the compressors/tire pumps take time to inflate, it is recommended to inflate the board by hand until it becomes difficult to pump, and then use the adaptor to top off the pressure.