Siemens 3RU2126-1CB0 Thermal Overload Relay 1.8-2.5 A. Overload relay 1.8...2.5 A Thermal For motor protection Size S0, Class 10 Contactor mounting Main circuit: Screw Auxiliary circuit: Screw Manual-Automatic-Reset. It belongs to SIRIUS 3RU2 thermal overload relays.