The 3RF3150-2AA24 is a 1-pole SIRIUS 3RF31 solid-state relay in a 22.5 mm wide package, rated for 50 A continuous load current across a 48-460 V AC load circuit, switched by a 110-230 V AC control voltage. It uses spring-loaded terminals and is designed for mounting on an available cooling surface — meaning the panel or chassis metal acts as the heatsink, not a separate finned unit. If you're replacing a failed electromechanical contactor on a heater bank, conveyor motor, or lighting load that cycles hard, this SSR takes the arc wear out of the equation.
The 22.5 mm width fits standard DIN-rail spacing, but the critical detail is the cooling surface requirement. You bolt the relay's base plate directly to a clean, flat metal panel — the datasheet's thermal curve depends on that interface. No screw torque to check, which speeds up panel wiring on a row of these.