Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number EST-40R-S-B found under by Cressall Resistors Ltd. The National Stock Number assigned to this part is 5905994941950, and the Federal Supply Class is 5905 Resistors. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like EST-40R-S-B.