Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 3971 4 found under Light Marker Distre by Acr Electronics Inc. The National Stock Number assigned to this part is 6230016414579, and the Federal Supply Class is 6230 Electric Portable And Hand Lighting Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 3971 4.