Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 1990-0593 found under Coupler Optoelectro by Hewlett Packard Co. The National Stock Number assigned to this part is 5980010846405, and the Federal Supply Class is 5980 Optoelectrical Devices And Associated Hardware. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 1990-0593.