Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number SY4025 found under Lamp Incandescent by Calumet Photographic Inc. The National Stock Number assigned to this part is 6240008114640, and the Federal Supply Class is 6240 Electric Lamps. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like SY4025.