Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 931-1820 found under Light Indicator by Allied Electronics Inc. The National Stock Number assigned to this part is 6220015491909, and the Federal Supply Class is 6220 Electric Vehicular Lights And Fixtures. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 931-1820.