5SY4102-7 Sentron 5SY4 MCB, 1P Poles, 2A Curve C, 250 V, 440 V AC, 250 V, 440 V DC. Make safety a priority in your workplace with this effective MCB from Siemens. The single-pole unit provides protection against short circuits and overloads in electrical systems. You can also use it to quickly and easily isolate a circuit for inspection. It has dimensions of just 90 (L) x 17.5 (W) x 76mm (D), so saves space in your cabinet. Installation’s a breeze, as you simply clip the breaker onto your DIN rail.