Yeah, they claim it's lighter but I don't feel any difference from any other microwave this size. Instead of a transformer they use a pulse-width converter. That is what Panasonic calls it themselves. Not exactly an "inverter" by the normal use of the word. In normal "tech" jargon, an inverter changes DC current into AC. A "converter" changes AC current into DC. To be technical, I guess with the "pulse width modulation" process - they change AC to DC (convert), then change the frequency, and then change back to AC again (invert) - to make inductive heat. Many devices do that so I'm not sure why they market it as an "inverter" microwave. But I guess that sounds better then a "pulse width modulation" microwave.
The main claim-to-fame with this mircowave IS the PWM control.
Regardless of the name, it does work. Great for use in a camper that runs of a battery-to-inverter AC power supply. That because there are no high-amp spikes like in a regular microwave.
I ran a test on an AIMs 1500 watt mod-wave inverter (rated 3000 watt surge). It cannot power a conventional 700 watt microwave. Now - I tested the Panasonic 900 watt "Inverter" microwave and it works fine.
At power level #1 - it draws 2.7 to 4.5 amps. Never spikes above that.
At power level # 5 it draws 6.7 amps steady.
At power level # 10 it drew 14.2 amps and tripped the breaker in my 1500 watt inverter. But that was due to low DC battery voltage. I started the engine in the camper and ran the test again and it then worked fine.