We have a very odd shaped window and it was hard to find a shade to fit the space.  What we really needed were mounts that we could fix to inside of window side (not top - due to arch). After a trip to Hardware Store, bought an "L" shaped bracket, attached the top  mount (inside mount) to the bracket, then was able to attach to the side of window.  It worked out very well and looks very cute in daughter's room. The shades provide light blocking privacy without total blackout.  Love them!