1. upper part and lower part unscrew
2. Insert the top part with the associated seal into the sink, making sure that the appropriate port is aligned with the overflow from the basin.
3. From below, first attach the sealing ring, then possibly align that everything is centered again and fix the lower part and tighten by hand.
4. briefly tighten the lower part with a pipe wrench.
Without having the base with pliers tightened it trickled after a few seconds. It is therefore not the pop-up valve when it trickles but remember that the two great seals are not pressed firmly enough.
As described above mounted, the shutter keeps absolutely tight.
