Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 8557972-2 found under Regulator Voltage by L3 Communications Corp. The National Stock Number assigned to this part is 5963012819660, and the Federal Supply Class is 5963 Electronic Modules. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 8557972-2.