Was checking out DD's site and saw an example of how they don't let engineering get in the way of marketing.
They are advertising a power inverter for running AC pumps from a PSU. From the specs:
"Modified sinewave output voltage"
Typically this statement means an output like the signal shown below in red.
A modified sinewave like this is fine for a lot of electronic items, but it is likely to make a pump run very hot, and may well result in the premature death of any pump it is used with.