Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 40-1-57 found under Glass Liquid Sight Indicator Fla by Brooks Instrument Llc. The National Stock Number assigned to this part is 6680000614157, 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 40-1-57.