The BUA-40/4 is a 4-pole Type 2 Surge Protective Device (SPD) designed according to EN 50539-11 standards for safeguarding 385V electrical systems. It offers a maximum open-circuit voltage of 385V, a nominal discharge current of 20kA, and a maximum discharge current of 40kA (8/20 µs), with a voltage protection level (Up) of ≤1.8kV and a rapid response time of ≤25 ns. The SPD features green/red LEDs for operating and fault indication, an optional remote changeover contact, and is designed for easy installation on 35mm DIN rails. With IP20 protection and CE certification, the BUA-40/4 ensures reliable and safe protection for industrial and commercial installations.