Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number B55-1-1961 found under Belt V by American National Standards Inst. The National Stock Number assigned to this part is 3030005290466, and the Federal Supply Class is 3030 Belting Drive Belts Fan Belts And Accessories. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like B55-1-1961.