a mixer tap assembly is shown which has a mixing chamber for mixing fluids from two inputs , and a mix controller to control the ratio of fluid flow into the mixing chamber from the inputs . the mix controller includes a mix actuator which operates a mix control apparatus , such as a rotatable sleeve , which is connected to a mix valve apparatus associated with the mixing chamber . the mix actuator and a fluid outlet are mountable on or above a work surface via a mounting apparatus , while the mixing chamber is mountable below the work surface . furthermore , the mix control apparatus and an output conduit , between the fluid outlet and the mixing chamber , pass through a bore in the mounting means , so minimising the footprint of the mixer tap assembly on the work surface .