This roll formed screen frame is a good substitute for 1966-68 Airstream extruded screen frames. It is designed as a replacement frame for trailer windows without their own screen mounting channels.
It is made of .020" thick mill finish aluminum and has a 5/16" flange and have an overall dimension of 1" x 3/8".
Sold in 72" lengths. You will need to miter cut your corners and insert the screen frame corner pieces (sold separately as VTS-095).
Use a .165" spline with aluminum screen or a .185" spline with fiberglass screen.