This easy to use jiggle siphon valve works by vigorously shaking the hose while immersed in liquid to generate a flow. To stop the flow, simply remove siphon valve from liquid. Ideal for siphoning & transferring most liquids such as water, petrol, diesel and kerosene. Great for refueling boats, lawn mowers, motorcycles & emptying ponds, tanks and water beds. Inner hose diameter: 12.5mm (1/2") Hose length: 1.5 meter (approx. 5ft)