Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number S4003MS3 found under Semiconductor Device Thyristor by Teccor Electronics Inc. The National Stock Number assigned to this part is 5961011655167, and the Federal Supply Class is 5961 Semiconductor Devices And Associated Hardware. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like S4003MS3.