It a sine wave inverter. I wouldn't even attempt that with a square wave inverter. The washing machine was $450 and it has a microprocessor controlled stepping motor.
I tried to find something simpler, but you can see how tight the fit is. There are very few machines that size and none for sale locally. I had to order the Avanti from Wally World and have them ship it to a store for me to pick up.
The Roper that's in the 2nd apt utility room is mechanical timer and plain jane motor, but it pulls 1200 watts continuous on some cycles. I can't even run that from a small generator I have, so the last hurricane, me and the neighbor in #2 had to borrow a generator to do clothes.