I used some of this film to analyze my tires' contact-patch (the area that actually touches the road). I wanted to find the PSI that resulted in even pressure across the width of the tire (these are oversized tires so I can't just rely on the OEM recommended pressures).I did some pressure estimates and found the "extreme low" film was probably what I wanted, so I ordered a small sample to be sure. (I recommend you do the same to make sure you're using the film appropriate for the pressure-levels you're trying to measure before buying a larger quantity.)I drove over the sample piece and it worked, so I decided I had the right pressure-level of film. I will say that the sample produced a much lighter-colored impression than the larger quantity of film I ordered later, which makes me wonder if they're using expired product for samples...anyway, it all worked out, but maybe keep that in mind if you try some samples.When I got the larger sheet, I cut it into strips to measure how inflation-pressure changed the weight-distribution across the contact-patch. The results are visible in the photo.The differences are rather subtle, so it's easiest to compare the one that says "50" (PSI; far right) with the one that says "16" (far left). If you check the bottom edge of both, you'll notice that at 50 PSI the bottom is lighter in color, meaning less pressure there---which is expected. The center at 50 PSI however is darker, which again is expected.I suspect that the person who says the film didn't work either had the wrong type of film (too high or low a pressure rating) or didn't understand the instructions---which is actually understandable because the instructions need considerable improvement:This is because the instructions don't accurately describe the "donor" vs "receiver" film: what they *should* say is that the donor film is clear and the receiver film is white---period. Instead they describe both as having one white side, which isn't true and is totally confusing. So that could be why that person ended up unhappy.You do have to be quite careful with the film not to crease or contaminate it: I cut my film into strips with a desktop paper-cutter which apparently had some oil on its mechanism, and some tiny oil-droplets landed on my film which created defects you can see in the photos. So it's quite fragile in that regard.You should also inspect the film carefully after receiving it to make sure it wasn't creased or contaminated before you got it---the white horizontal lines on the bottom of my test-strips were caused by a crease on the donor film that was there when it arrived. Because this wasn't a life-or-death situation I just used it anyway.All you really have to do in the end is create a "sandwich" of the donor and receiver films with the glossy sides facing outwards, and then apply your pressure. The result will tell you exactly what you need to know, and it will be obvious which film is which after you do this.In short, I found this to be an excellent product which helped me find the answer I was looking for.

Worked as advertised to measure pressure within the specified range.

This product did not work at all and expensive, I would recommend not to buy this product