Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number M1 31 1 3 8S found under Moisture Indicator by Henry Technologies Inc. The National Stock Number assigned to this part is 6210013280113, and the Federal Supply Class is 6210 Indoor And Outdoor Electrical Lighting Fixtures. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like M1 31 1 3 8S.