SEEYE Blackout PVC Light Blockers for Window Blinds and Shades, Light Blocking Strips Block Light Along Two Sides of Windows for Bedroom Nursery(White, 29.5" L x 1.4" W x 0.8" H-4pcs)

No bloquea la luz bien

1- they glow yellow when the sun hits them so don’t believe the blackout claim it’s false2 - they are brittle when you cut them and can crack unevenly3 - not wide enough for some gaps so measureBut does help. Just not everything they claim it is.

Although the product listing says you can "cut them to suit your needs, cutting them with kitchen scissors," we tried that -- and promptly broke a nearly new pair of Fiskars scissors! Not to mention, the magnetic strips used to hold the strips are so thick that you MUST have at least 1/4" of extra space on each side of the shade or there won't be enough room to install them. Our shades were properly measured and installed so we could not use the magnetic strips, leaving us no choice but to glue them into place instead (after cutting them with a hacksaw). Bottom line: we never would have bought such an expensive product had we known what a hassle they were to work with.

Easy to install and really blocks out the sun

Our kids room gets direct Sunlight in the morning so we decided to give this product a try. First, very easy to apply on, don't think the magnetic feature is really necessary (still needs double sided tape). The issue, from video, it shows the product with Shades, but we have Blinds. Although it does block the sides but the horizontal part of the blinds still have light peeks through. I suggest for Shades for this product.