Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number L1-E3 found under Switch Lensometer O by Marco Ophthalmic Inc. The National Stock Number assigned to this part is 5930014162308, and the Federal Supply Class is 5930 Switches. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like L1-E3.