Review on 🌑 Total Blackout Window Film: 100% Light Blocking Glass Door Film for Day Sleep & High Privacy - Etched Tulip Design, Room Darkening Window Cling - No Glue/Heat Control/Anti UV - 17.5In. by 78.7In. by Melissa Jones

It's definitely 100% dimming. But the quantity per roll is sooooo small. The attached photo shows a full roll. So I immediately reordered. And he's black too. The sun hits the window she's standing on and I can feel it getting very, very hot. The heat radiates off him like crazy. So I certainly wouldn't rely on that for heat protection. I'm pretty sure it will make the room warmer. I work nights so got this because the curtains leave too many gaps. So it definitely serves the purpose of darkening the room. And $20 a window is actually not that bad.