Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number R1-6163 found under Electron Tube by Servino And Associates Inc. The National Stock Number assigned to this part is 5960001005900, and the Federal Supply Class is 5960 Electron Tubes And Associated Hardware. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like R1-6163.