The ABB S204‑D16 miniature circuit breaker is a 4‑pole compact overcurrent protection device designed for use in low‑voltage AC electrical systems. It features a D‑type trip characteristic, making it suitable for circuits with high inrush currents such as motors and transformers. The breaker provides thermal and electromechanical protection against overloads and short circuits, and is DIN‑rail mountable for easy installation in distribution panels. Its robust construction and compliance with international standards make it suitable for residential, commercial, and light industrial applications.