Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number FT81U found under Lamp Flashtube by Siemens Energy And Automation Inc. The National Stock Number assigned to this part is 6240013061137, and the Federal Supply Class is 6240 Electric Lamps. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like FT81U.