Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 13-6618-10S found under Amplifier Direct Cu by Gould Instrument Systems Inc. The National Stock Number assigned to this part is 5996013712958, 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 13-6618-10S.