This bolt is locked without voltage, the locking is made by an incorporated spring. With an electrical signal the bolt turns to unlocked. The key has two positions, in the locked position the key cannot be removed. To remove it, it is necesary to
unlock the bolt.

This locking bolt is double coil bistable solenoid, where the stroke movement from initial (unlocked) to final position (locked) is made by electromagnetic forces when coil 1 is feeded. The return to initial positions takes place by an inverse polarizing pulse (when coil 2 is feeded) combined with an incorporated spring.