Dudley Hydroflo Float Valves are Equilibrium Quiet Filling Part 4 Valves, manufactured to BS1212 standards. These are available in side or adjustable bottom inlet from 8? to 11.1/2?, with either a plastic or brass tail option to help prevent cross-threading. The unique float arm makes it impossible for the float to become detached. Filter removal is made quick and simple by providing a key attached to every diverter, without causing any damage to the valve. Simple and easy to install, this valve is a great replacement for any cistern.?