Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number MM-3130B-11M-S found under O Ring by Metrex Valve Corp. The National Stock Number assigned to this part is 5331005840266, 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 MM-3130B-11M-S.