AQUALINE WC flush valve DN 20 for installation behind a wall, for enhanced safety in applications with an impending risk of vandalism, e.g. in prisons. Pushbutton flush valve with remote activation and lockable water quantity regulator. Flush flow rate and flush water volume adjustable. Complete with flush-pipe union and screw fastening. Stainless steel cover plate with threaded rods for vandalism-resisting installation and metal pushbutton operation. Wall-mounting box for pushbutton actuator, control lines and conduit included. Complete with fastening material consisting of threaded rods M8 x 500 mm, stainless steel mounting cross-rails, stainless steel washers and stainless steel hex nuts.