The Pro 48 Refrigerator is an elite model of Sub-Zero. It is composed of 100% solid steel, comes in two different versions with one having the additional feature of a glass door. Freezer on the left. Refrigerator on the right. High performance through and through. Its vast interior, like its bold exterior, is designed of stainless steel. Available with or without a glass door, the PRO 48 may be built-in or freestanding using a kit.