The MEDIATOR system operates properly only if the distance between the face plate of the mortise lock and the striking plate of the electric strike is 2-5.5 mm.
If the distance is bigger, this can be decreased with this distance holder plate on the electric strike side.

For MEDIATOR electric strikes.
Angled distance holder plate. 356 x 24-28 x 2-3 mm.

Left-right mountable.