It did make difference in blocking the sun in a small arched window that I was unable to get a shade to fit.
Using for rv windows
Was a little hard to put up but easy to cut and it has made a huge difference in the temperature in our room by 10+ degrees.
This product started out great. The only thing that wasn't mentioned was that in direct sunlight it shrinks and peels off the window. **First day"I really regret purchasing this. Will have to find another to black out windows since husband work nights.