The 4230-T120-K0CE-5A is a single-pole thermal-magnetic miniature circuit breaker (MCB) designed for DIN rail mounting with toggle actuation and visual status indication. It features a rated current of 20 A at AC 240 V, screw terminals with a maximum tightening torque of 2 Nm, and supports cable cross-sections up to 35 mm². The device incorporates a positively trip-free snap action mechanism with characteristic curve C (thermal 1.05–1.30 × IN, magnetic 6.4–9.6 × IN) and meets IEC/EN 60947-2 and UL 1077 standards. It is rated for an ambient temperature range of -35°C to +70°C, offers IP20 degree of protection, and includes overvoltage category III coordination (Uimp 4 kV). This MCB is ideal for protecting cables, motors, generators, transformers, and industrial control systems in commercial and industrial applications.