Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number ESI-235-2-176-039 found under Coupler Indicator by Excalibur Systems Inc. The National Stock Number assigned to this part is 6625016046322, 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 ESI-235-2-176-039.