GE's WB39X10003 microwave glass cooking tray is designed to replace cracked, broken or worn plates and has overall diameter of approximately 12 1/2 inches, Glass cooking trays designed primarily for microwaves are manufactured with slots that allow the dish to sit securely on the track found at bottom of the appliance., GE's WB39X10003 microwave glass cooking tray is designed to replace cracked, broken or worn plates. This tray has an overall diameter of approximately 12 1/2 inches and an outside turntable track diameter where the wheels fit of 10 1/4 inches., The WB39X10003 microwave glass cooking tray will fit in most GE appliances beginning with the following model numbers:, This turntable tray (part number WB39X10003) is for microwaves.