Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 2 5X52 21B6 found under O Ring by Le Joint Francais. The National Stock Number assigned to this part is 5331142812401, 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 2 5X52 21B6.