Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number MS9021-220 34-52X3-53F641A found under O Ring by Alkan. The National Stock Number assigned to this part is 5331005853355, 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 MS9021-220 34-52X3-53F641A.