Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 38-1165-0021 found under O Ring by Regal Beloit Corp Durst Div. The National Stock Number assigned to this part is 5331012283246, 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 38-1165-0021.