Turn clockwise for locking, Turn anticlockwise for unlocking.Mount the evaporation flask:-Place the evaporation flask (4) on the vapour tube.-Turn the plastic nut (2) with the clip (3) anticlockwise until the dlip can be put on the flange.-Now turn the plastic nut clockwise until the clamp is hard up against the flange. When doing so, hold the locking device (1) on the vapour tube.Remove the evaporation flask:-Hold the locking device and loosen the plastic nut by turning it anticlockwise. This releases a tightly clamped evaporation flask.-Hold the evaporation flask at the flange and open the clip.-Remove the evaporation flask.-Check that the locking of vapour tube is still closed!●Mount the condenser seal