Bull 89975 Stainless Steel Single Vertical Door. Commercial quality polished 304 stainless steel construction for durability and lasting appearance. 304 stainless steel has excellent resistance to corrosion and heat. Cut Out Dimensions: 23-inch H by 15 3/4-inch W by 1 1/2-inch D. Please contact Bull Outdoor Products at 800-521-Bull(2855) with technical questions.