A Hebo auxiliary fuel / petrol tank, with a capacity of one litre. This straps to the top of your fork stanchions, with the tie wraps provided. The instructions are not so good, but basically you can use this in three ways. You can siphon the fuel into your tank, connect it directly to your carburettor, or ideally connect it to the vent hose on your fuel cap. The fuel should then automatically siphon over into your main tank.