A:Answer Hi Emma! Thank you for reaching out. For the Frigidaire GMBS3068BF microwave, even with a trim kit, the maximum cutout width is 25", so your opening of 25.75" is too wide. While a trim kit can cover gaps cosmetically, it cannot provide the structural support or secure mounting needed for the microwave, and attempting to install it in an oversized space could make the unit unstable, misaligned, or unsafe, and may void the warranty. The only safe options are to reduce the opening to 25" or less or select a model designed for a wider space. - Reed