GE Profile 30 Electric Downdraft Glass Cooktop / Stovetop – TESTING VIDEO. Cutout Dimensions: 28-1/2″ x 20-1/8″. Glass Dimensions: 29-7/8″ x 21-7/8″. The cooktop was tested and the downdraft and burners work great as shown in video above. Expect minor scratches, scuffs, and grease. What you see is EXACTLY what you get, nothing more or less. Any testing that has been done will be listed in the description. If you have any problems with your item, please let us know ASAP so we can do our best to resolve any issues.