Frequently used as a hand pump in boats for supply to the out-board engine.
Hand bulb primer to suit petrol of comes with a way valve installed to help quickly prime the system.
It made of high quality rubber and aluminum; Has the metal ends and works well
Suitable for carburetor and low pressure systems.
If you want to use it as a siphon, you need a workaround, but you need two "T" joints, a small plug valve and an additional hose.
It has two valves, at each end. When you stop pumping, it will actually stop, there may be a small amount of water dripping, making it just a pump, not a siphon.