MDSX40, Cutler Hammer, Magnum DS, type MDSX, drawout or fixed mounted, double frame, 3P, 3PH, 4000A, 600V, 200kA@600V, current limiting, 40°C, bolt-on, complete with interchangeable Digitrip, LI - Long-Time and Instantaneous trip functions, load side lug terminals, thermal magnetic, low voltage power insulated case circuit breakers