750 MCM Conductor – 500 MCM Aluminum Pin Terminal – Yellow
https://nsiindustries.com/product/750-mcm-conductor-500-mcm-aluminum-pin-terminal-yellow/
These copper pin aluminum connectors are rated for aluminum conductors with a pigtail type copper pin designed to facilitate termination of aluminum conductors into copper connectors. The POLARIS compression design creates a permanent, vibration-resistant connection that you can rely on with low contact resistance.