Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number M23-E4WWL2 973B REL 9A found under Electron Tube by National Electronics Corp. The National Stock Number assigned to this part is 5960014547064, 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 M23-E4WWL2 973B REL 9A.