Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 72-1-3-1 found under Amplifier Subassemb by Celtech Corporation. The National Stock Number assigned to this part is 5996010785508, and the Federal Supply Class is . Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 72-1-3-1.