2 Port Aluminum Dual Rated Transformer Stud Connector 500 MCM - 4 AWG Aluminum dual rated transformer stud connectors are versatile and reusable set screw connectors made from 6061T-6 aluminum alloy for superior electrical and mechanical performance. Clear plated for low contact resistance- stud is tin plated copper which provides low contact resistance for connection to transformer. For use with copper and aluminum conductors. Meets or exceeds ANSI C119.4 Class A. Rated 600V. Temperature rating 90 degrees C.