Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 12R4W-1B 4B-51 found under Refrigerator Mechanical Mortuary by Csi Industries Inc. The National Stock Number assigned to this part is 4110015544301, and the Federal Supply Class is 4110 Refrigeration Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 12R4W-1B 4B-51.