Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number P404B found under Ballast Lamp by Sim Kar Lighting Fixture Co Inc. The National Stock Number assigned to this part is 6250004100097, and the Federal Supply Class is 6250 Ballasts Lampholders And Starters. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like P404B.