Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number B2-1238 found under Idler Pulley Assemb by Marshall Engineered Products Co. The National Stock Number assigned to this part is 4130008326926, and the Federal Supply Class is 4130 Refrigeration And Air Conditioning Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like B2-1238.