FMM 4290-0050 (for walls 400 mm). ---------------------------- FMM 4290-2050 (for walls 500 mm). ---------------------------- A classic, patent protected FM Mattsson-design. The tap is guaranteed not to freeze, even if the garden hose is left connected. The actual valve housing and approved return-valve are mounted on the inside of the wall in a warm environment. Excess water in the exit pipe empties automatically when the flow stops. A control washer stops the draining water from wetting the house wall. The control washer is stainless steel and the valve housing and exit pipe are chromium plated brass.