End caps for my old 24 ft type III extension ladder.  The plastic ends had broken off long ago. They cover the sharp ends and perhaps provide a little protection for myself and whatever I am leaning it against.  These slide over the rails that make up the sides.  Can't remember what brand but you can tell if they would work by looking at the open end of the STL to see the profile of the aluminum rail.

Print in something more durable than PLA,  guessing PLAs brittleness and quick softening due to heat would make these fall apart.  I printed in PetG with thick walls and high infill.  Seems to be holding up, but no guarantees.  Two holes in the side matched the rivet location where the old plastic was secured.  You can just glue the caps on or secure with a pin.