Better Bilt window parts

The plastic spacers clip onto the top and bottom of the window frame and keep the screen tight against the outside of the frame.
The insert (first picture) snaps into the side of the frame and flexes inward (with pressure on the screen) to allow removal of the screen.

There are no markings on the parts but the windows are "Better Bilt" brand.

I reexamined the upper spacers and find they do not clip onto the frame but are inserted from the inside after the screen is in place.
The upper ones do not have the clip along one edge as the lowers do.