The hydraulic helms are of the axial pistons type. The helm housing is in aluminium with bronze gears and cylinder block for greater durability and longer life. The P20, P30 and P42 models are supplied with a built-in non return and relief valve. For all the other models a non return valve shall be mounted separately. The hydraulic helms are supplied without any fitting. Complete kit of fittings are available separately, which shall be specified when placing the order. The codes and descriptions of the different kits can be found on the price list.