Monoblock valve 1 lever predisposed for CARRY OVER

The ML type distributors have a standard arrangement for connection in Carryover. This connection is made by closing the septum visible from the hole shown in the figure with a 1/4 "Gas dowel.
The threaded hole itself is then used for the connection with the downstream distributor.
If the threaded hole in question is also plugged, the open center distributor is transformed into a closed center distributor.