How big a room will it scent?

At Home does not publish a coverage rating for this model. Its 9.2-inch height and 4.7-inch width suit a bedroom, office or entryway rather than an open living area.

Does it need At Home oils?

It is sold as an oils diffuser, so it is designed for fragrance oils rather than plain water alone. Other brands of diffuser oil should work, but check the instructions for any recommended dilution.

Does it have a timer or auto shut-off?

No timer or smart features are stated for this model. Plan to switch it off yourself, and never leave it running unattended.

What comes in the box?

Expect the diffuser itself; oil and other accessories are usually sold separately. Confirm the contents with At Home before ordering if you need a power adapter included.

Is this diffuser good value?

It is the only new model on record from a single seller, At Home. With one seller there is no lower new price to beat, so judge it against what similar metal diffusers cost locally.