Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number GK-4-21C-1 2 found under Connector Plug Electrical by Pei Genesis Inc. The National Stock Number assigned to this part is 5935002581563, and the Federal Supply Class is 5935 Connectors Electrical. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like GK-4-21C-1 2.