Rubber shell connectors also called Packard connectors. Connectors are part number MS27142-1 (male electrical connector/female rubber shell). Made in USA. Ozone resistant rubber.
Connector assembly sold individually, price is for one each of: rubber shell, C washer, and terminal pin.
Terminal ends can be soldered or crimped on to the wire. These are made for 12 AWG stranded copper wire. Connectors are used on many Military vehicles but are good for custom projects too.
Note- this 12 AWG connector is often used on main power feeds to panels, motors, heaters, floodlights, etc.