Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 3401-B-12 found under Gage Soil Density by Troxler Electronic Laboratories. The National Stock Number assigned to this part is 6695010733396, and the Federal Supply Class is . Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 3401-B-12.