Plug-in base in a narrow design of 6.2 mm, comparable to a terminal block for accommodating a plug-in solid-state relay of the SSL1 series. The base has connection terminals with spring-loaded technology, accommodation of wiring combs for potential bridging, an LED display of the control status, a lever for easier installation or ejection of the solid-state relay and an internal reverse polarity protection with voltage adjustment for controlling the plugged-in solid-state relay. This base is suitable for all SSL1-JD/BD solid-state relays with a control voltage of 5 to 24 VDC.