The purpose of the header tank is to allow for the steering gear oil to expand and contract due to the temperature variations. Also it is usefull to keep the helm pumps reservoirs full agaist leakages to tank if an auto-fill system is not available. Header tank can be used with manual filled system as well as on an auto-filled system. If used with an auto-fill system, breather should be sealed and it should be vented to the HPU tank. Header tank must be installed above the highest helm pump onboard. Header tank is made of stainless steel and have a capacity of 2 lt. Sight glasses are available in standart.