Optimum Balance Products (OBP) continue their range of high quality and functional alloy products with these 'Dark Matter' alloy water header tanks. Dark Matter is a Matt black coating which is hard wearing and resistant to petrol, oils, acid and alkali. This makes it ideal for use in competition engine bays which are subjected to the harshest of conditions.Ideal for bespoke coolant systems in Motorsport applicationsCoated in 'Dark Matter' for a long lasting great looking Matt black finishAircraft grade aluminium construction which is pressure pressure tested for quality assurance.Tanks accept standard size radiator cap (not included)Designed to meet requirements of serious competitors and enthusiasts alike, the header tanks have been developed to be installed in bespoke, one off or competition installations where original header tanks are not suitable. At home on the track or for fast road use, the header tanks are manufactured to the usual highest OBP quality with suitable inlets and