MARS 61611 1 NC 25-60A Definite Purpose Contactor Auxiliary Switch is Engineered for Today's Most Demanding Commercial Refrigeration, Air Conditioning and Electric Heating Systems. The Enclosed Body Provides a Quieter Running Contactor and a Longer Life Expectancy while the Oversized 'Arch Window' Simplifies Wiring. The High Performance Copper and Brass Conductors Maximize Current Carrying Capabililty, Creating a Cooler Running Contactor