Bosch Thermador Oven Telescopic Extension Rail 478316 00478316 Extension rack (part number 00478316) is an original equipment manufacturer (OEM) part that fits Bosch wall oven models starting with HBL8450UC, HBL8650UC and HBL8750UC. Extension rack 00478316 also fits Thermador wall oven models starting with ME301E, ME302E, MED302, MEM301, MEMC30, MEMCW3, MEMW30, MEW301, PO3010, PO3020, POD301, POD302, PODC30, PODM30, PODMW3, POM301 and POMW30. Ball bearing rack guides allow the rack to extend fully without tipping over even when holding a heavy roasting pan. The extension rack is 23-1/2 inches by 15-1/2 inches. Extension rack 00478316 replaces part number 478316.