The item in the image is a DG-C40 DC Surge Protective Device, specifically designed for photovoltaic (solar) power systems to protect against lightning and surge voltages. Model/Brand: DG-C40 by D>. Voltage Rating (\(U_{c}\)): 1000V DC. Surge Currents: Nominal Discharge Current (\(I_{n}\)): 20kA; Maximum Discharge Current (\(I_{max}\)): 40kA.