QY-1-13-DM-U2-20 is a single-pole miniature DC circuit breaker designed for low-voltage DC power distribution and protection applications. It features a 20 A current rating with a medium time delay (U2 curve) tripping characteristic, 80 Vdc operating voltage, and an ultimate short-circuit breaking capacity of 10 kA. The breaker employs hydraulic-magnetic technology with 100% rating capability independent of ambient temperature, operates reliably across -40°C to +85°C, and is housed in a compact 13 mm wide module with dual DIN and mini rail mounting options. It is VDE, EAC, and CCC approved, CE certified, and UL listed (UL 489A), making it suitable for electrical isolation and protection in renewable energy systems, battery management, telecommunications, and industrial DC power applications where precision tripping and compact installation are essential.