They have check valves and vent tubes. The shank is 3/8npt. Both ready to use on your nice hit miss engine.The item “Lunkenheimer paragon hit miss engine oilers” is in sale since Saturday, April 18, 2015. This item is in the category “Business & Industrial\Light Equipment & Tools\Stationary Engines\Parts”. The seller is “randiandzach” and is located in Wolcott, Indiana. This item can be shipped to United States and to Canada and to Mexico.