Shelley was a key member of a close circle of visionary poets and writers that included Lord Byron; Leigh Hunt; Thomas Love Peacock; and his own second wife, Mary Shelley, the author of Frankenstein.
If the 900 watts means the input power, then 1000 w inverter would be ok. If the microwave produces 900 w of cooking power, you will need a bit more, maybe 1200-1400 w if you don't know what the input power rating of the microwave is.
These replace the regular vent above the stove, and will exhaust the heat and fumes from cooking just like the regular vent. But in addition, it's a microwave. It can be anything from an inexpensive unit ($200 range) to a microwave/convection oven ($400 to $600 range) .A microwave/vent is 30 wide, and uses up 15 in height. Pretty much the same as the built-in microwave above, but it doesn't require a cabinet to set it in.ut in addition, it's a microwave. It can be anything from an inexpensive unit ($200 range) to a microwave/convection oven ($400 to $600 range) . A microwave/vent is 30 wide, and uses up 15 in height. Pretty much the same as the built-in microwave above, but it doesn't require a cabinet to set it in.