Does it work the same at night time or we can see inside the room from outside at dark?

As with all one-way materials, this material works based on light ratio. Whichever side of the glass has more light, this is the side that will be seen. While the Silver Gray One Way does offer more privacy, it will still not block visibility entirely in the evening if lights are on. Currently there is no product available in the market that allows for 24 hour one way visibility.