The gats jar is the first finest and only fuel analysis tester capable of separating non-petroleum contaminants and thereby purifying water and debris from contaminated avgas and jet fuel. This allows extracted fuel to be put back into the aircraft and not on the ground without the fear of reintroducing contaminants back into the fuel system. Once the fuel is sampled, the built-in screen separates solids and  non-petroleum contaminants so that only clean fuel is returned to the tank.  It also gives a visual display of AVGAS contaminated by jet fuel, and can be used with any petroleum fuel grade and octane, including Jet A fuel, automotive gasoline, and diesel fuel.  Made of strong plastic with a wide mouth.  Holds 16 ounces.