Our front room, that faces the afternoon sun, has two enormous Victorian windows. We have tried insulated black out curtains, other sunblocking film products, etc. this is simple to apply and works to reduce the heat and temperature in the room. Does not completely block out heat. Effective enough to make the room comfortable, rather than so hot we sit there sweating like we are in a sauna. Like that we are also able to look out the windows and still have privacy. There are video instructions foSee full review