Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number MR-1-OPT-E-AND-H found under by Tenney Engineering Inc. The National Stock Number assigned to this part is 6640013899277, 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 MR-1-OPT-E-AND-H.