Originally Posted by fadetoblack6902
Yeah it's hollow. It's too skinny and long to be a pedal axle. It is 4 inches long, and the skinny end is 1/8 inch across. The threaded end is 5/16 inch across.
Well, 5/16" is too small for a pedal axle certainly and it doesn't look like any other bike part I've ever seen. I'm gonna throw my vote in with those who think it's an air gun extension. 5/16" is a pretty common size for air hose and pump fittings, I believe.