Remote display for trailer coupling

The coupling (10) has coupling bolt (14) secured in coupling position by securing pin (28) against displacement. The pin is displaced between preparation state in which coupling bolt is located in release position in direction different from coupling position and securing state in which bolt is located in coupling position. A sensor (38) is arranged to detect whether pin in specific set position is monitored or not. The sensor has magnetic and electric field generating element (44) arranged in state surrounding trajectory (T) of pin by moving into and from to-be-monitored position.