Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number NO PRIMARY REF 99-910-1820 found under Adapter Electrical by This Ncage Is Used To Inform That. The National Stock Number assigned to this part is 5975999101820, and the Federal Supply Class is 5975 Electrical Hardware And Supplies. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like NO PRIMARY REF 99-910-1820.