Is this a 27-inch or 30-inch wall oven?

It is a 27-inch model. Measure your cabinet cutout before ordering, because a 30-inch opening will not fit it without modification.

Does it need a 240V circuit?

Yes. It runs on 240V, so it needs a dedicated electric circuit like most built-in wall ovens. Confirm your wiring with an electrician before installation.

How does the microwave part work?

The microwave is built into the upper section of the unit, above the main oven cavity. You get microwave speed and a full oven in one built-in footprint.

Yes. The oven has a self-cleaning cycle that burns off food residue at high heat. You still wipe out the ash afterward.

Can I control it from my phone?

No. It has no app control or smart features. All settings are made at the control panel.

What is the main trade-off versus a separate oven and microwave?

You save cabinet space and get one built-in unit, but the microwave cavity is smaller than a countertop model and the 27-inch oven is narrower than a 30-inch wall oven.