The M39019/01-227S is a one-pole, magnetic, sealed, and trip-free circuit breaker designed for low-power overcurrent protection. It features a current rating of 4.0 amps and is rated for a maximum of 50V DC or 240V AC at 60 Hz and 400 Hz. This model is characterized by a standard 'A' time delay curve, with a maximum DC resistance of 0.10 ohms and maximum impedance values of 0.10 ohms at 60 Hz and 0.12 ohms at 400 Hz. As a part with the 'S' suffix, it is supplied in configuration 2 with screw terminals and an insulating block, making it suitable for demanding military and aerospace applications.