I am looking for plastic strips that act as anti-friction guides along the vertical edges of the lower (sliding) sash of the single-hung windows.
Thanks,
Armen
There is one strip along the left and another along the right vertical edge of the lower (sliding) sash of the single-hung windows in my house.

1. The image on the left is the end-view showing the strip (painted black to show better), which slides into the groove of the aluminum frame.
2. The image on the right is a dimensional sketch of the strip.
Any suggestions as to where I might be able to locate these strips or something similar?
2. The image on the right is a dimensional sketch of the strip.