This Device is for Airplane Modelers that have their Engines and Fuel Lines in "hard to get at Places such as Cowlings.
One-Piece Valve Assembly installed into Airplane with Convenient Fueling Probe for Refueling.
Overall length (front to back) : 13/16 (20mm)
Mounting nut diameter (what is seen on outside of cowl) : 1/4 in.
Hole size (drilled through cowl) : 3/8 in.
Length inside cowling : 1/2 in.