In the late 1960s, a device specification known as CU/AL (meaning copper-aluminum) was created that specified standards for devices intended for use with aluminum wire.

What does Al-Cu mean?

In the late 1960s, a device specification known as CU/AL (meaning copper-aluminum) was created that specified standards for devices intended for use with aluminum wire.

What is Al-Cu wire?

The only twist-on for aluminum-to-copper connections. The Twister® AL/CU Wire Connector is the only UL Listed aluminum-to-copper twist-on connector that prevents aluminum oxidation while providing a secure connection. … For use only on copper-to-copper or aluminum-to-copper connections.