Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number KS4657 found under Switch Thermostatic by Bae Systems Information And Electronic Systems Integration I Dba Es Marine Syste. The National Stock Number assigned to this part is 5930001025929, 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 KS4657.