Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 21-19878 FIND NO 55 found under Cable Assembly Spec by Treadwell Corporation. The National Stock Number assigned to this part is 5995015862981, and the Federal Supply Class is 5995 Cable Cord And Wire Assemblies Communication Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 21-19878 FIND NO 55.