The Mobile Bed and Flow Visualization Unit (HVFLM-2) is a particularly useful unit to demonstrate the fluidization phenomenon in engineering. It makes it possible to study different situations of flow and mobile bed visualization related to civil engineering structures. This unit may be used mainly in two study fields. The first one is the investigation of mobile beds, which are related to water courses and civil engineering structures. The second one is related to the visualization of the flow in two dimensions. The HVFLM-2 unit consists of an horizontal channel through which a current of water flows slowly and at a constant depth. This channel allows to visualize the flow and the mobile bed in two dimensions as it has a large working surface (section: 2000 mm x 610 mmm). The upper part of this surface can be completely visualized during the practical exercises, without the need of assembling any accessory. The position of different models and structures in the channel, where the flow circulates around them, allows to carry out studies of mobile bed and flow visualization in a simple way. The unit is self-contained and it consists of an inlet tank with adjustable overshot, a channel with sand traps, a discharge tank, water storage tanks, a centrifugal pump, an electromagnetic flow meter and set of models. The unit includes the necessary instrumentation to measure the water level and the bed depth, formed by an instruments carrier and a gauge. The practical exercises with this unit are carried out by using water and sand. Ink is included for the two dimension flow visualization, to carry out flow studies around the models and to demonstrate the boundary layer.