Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number GS20399-1 found under Cap Protective Dust by Hamilton Sundstrand Corporation. The National Stock Number assigned to this part is 5340013290909, and the Federal Supply Class is 5340 Hardware Commercial. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like GS20399-1.