A:AnswerModel GCST16S1WSS is not compatible with a trim kit, as it's designed to be used on the countertop. We do have other countertop microwaves that have the option of being built-in with a trim kit, including PEM31SFSS.
A:AnswerThis model microwave is not designed or approved for a built-in type of application. We do not offer a trim kit that is compatible with this model. This microwave requires 3" of air clearance on each side and at the top as well as 1" of air clearance in the rear to ensure a safe and reliable installation. -Vikki@GEAppliances