It doesn't seem to be a real brand, Bauhaus sells it and its made in Taiwan. I'm sure there are similar or better films out there.
These photos shows how much the film dims the visible light: https://dropover.cloud/999162
The photo of the wall shows two areas, one area illuminated by the light passing through the filter and another small area illuminated by direct sunlight through the opening.
It's a window in a small room. The window has a top-open position which provides enough ventilation to take away heat that still manages to get in. Previously, this room was getting unbearably hot and now is much better(still hot on days with no wind though).
The difference this summer has been striking. In our bedrooms which are on the second floor, the sun feels hot through the windows. In the living room I can barely feel it.
We're up north so our home is well insulated, hence the summer sun tended to overheat the inside.
On the flip side, the glass we replaced was some 20+ year old two layer glass while the new were thick 3 layer stuff. They're vastly better insulating (heat and sound), so that alone was a huge plus compared to the old.
Have you found one that does not do this or do you have any comments about this risk?
However, if you simply don't want to be seen by people looking in from the outside, there are still some options:
If the inside is much darker than the outside, light from inside is overwhelmed by light from outside getting reflected back (the operating principle of "one-way" mirrors).
If the window is covered with a grid that only has small gaps (e.g. window blinds), it's hard to recognize objects on the other side unless your eye is close enough to look through a single gap.
If the glass has a rough surface (i.e. frosted glass), light that makes it through is scattered in different directions, blurring objects that aren't very close to the window.
Various combinations seem possible. (Frosted glass window blinds?)
There are window films that can block most of the light in frequencies which carries the energy and let the light from visible spectrum in, barely dimming the brightness and almost doesn't change the color.
I recently installed such a filter, I'm amazed everyday how the hot bright sun is so tamed once inside the house. Sometimes I open a window to let the full spectrum in just so I can put my feet on the spot of the unfiltered light and then on the filtered one and compare how hot it gets where the sun shines in full power and can barely heat once filtered. It feels like magic, like a winter sun that is bright but doesn't heat.
My grandma lives in an old house built with thick stone walls with tiny windows. It stays naturally cool but I really like large windows. IMHO, the humanity has advanced enough to have large windows and still keep it cool.