The ABB S204‑D63 is a 4‑pole miniature circuit breaker (MCB) from the ABB System pro M / S200 series, designed to provide reliable overload and short‑circuit protection in low‑voltage AC electrical distribution systems. It utilizes a Type D trip characteristic, which allows higher tolerance for high inrush currents such as those drawn by motors and transformers, while still offering dependable protective operation. The breaker is DIN‑rail mountable and features screw‑type terminals with clear ON/OFF position indication, making it suitable for residential, commercial, and light industrial applications