The J600 product line consists of Thermal Magnetic Circuit Breakers, Magnetic Circuit Breakers, and Molded-Case Switches rated up to 600 Amps and 600 Volts AC. These breakers are available with either non-interchangeable trips (designated type TJJ) or interchangeable trips (designated types TJK/THJK). Type TJJ devices ship fully assembled while types TJK/THJK ship unassembled unless specified on the order. TJK breakers are available in two frames, 400 ampere frame (125 to 400 amperes) and 600 ampere frame (250 to 600 amperes). Trip units are not interchangeable between frames. The WL catalog number suffix indicates that the devices come with Cu/Al line and load lugs. THJK4 2 POLE 600V 350 AMP