Does what it should as far as blocking the light which is what I needed to be able to watch TV during the day when a window reflected on the screen.  But I really would have preferred finding panels that were wider.  I ended up having to use the drapery pins to pin them to a shear curtain but don't expect it to work as a long term solution - too stiff and bulky to look neat behind my curtain.  They do fit on a small tension rod but was unable to install that due to plantation blinds on the window.

Pros: blocks out light
Cons: narrow, stiff fabric - hanging loops flimsy