Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number RTS-42-A-100-B-16-40-X1 found under Thermocouple Immersion by Hy Cal Engineering. The National Stock Number assigned to this part is 6685011442623, 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 RTS-42-A-100-B-16-40-X1.