Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number PKG F 6 4006Y D found under O Ring by Btr Valve Sealants Inc. The National Stock Number assigned to this part is 5331011825508, 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 PKG F 6 4006Y D.