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.
From countertop to built-in. Create a built-in microwave oven by pairing select GE countertop microwaves with a required matching trim kit. Built-in microwave trim kits (sold separately) fit either 27 or 30 cabinets seamlessly and allow for proper ventilation. You can install the microwave into your cabinetry alone, or above a wall oven. Built-in installation with a trim kit maximizes counter space and achieves a custom, seamless look for your kitchen.