Socket Screw, Flat Head Allen (called the socket bolt on some diagrams) inserts into the hinge pin and pivot pin causing the aluminum washer to hold those pins in place on the main door step assembly.
For Double Step Assembly 3440006
See parts manuals for compatibility and placement.
Compatibility: 1977 to Present Airstream
To view an interactive image of the Airstream Aluminum Double Step Assembly Parts Diagram click here.