Video at Amazon.com See Many reflectivity of the product can not imagine why a video (unfortunately only in poor mobile phone quality with direct HANDY LIGHT and a direct comparison with "standard" cat's eyes). To generate these comparatively extreme luminosity, the light source must be literally right next to the eye / sensor of the camera so do not be surprised if the are reflectors shine weakly on the first field trial. Just keep out the light source to the face and at eye level to get the maximum reflection strength, of course, but this is in indirect light source less always much stronger than commercially available cat's eyes. As a comparison, you are the reflectors of the other bikes in the immediate vicinity.
As such, the product is more than recommended, and is unfortunately all too rarely used in German roads. She's a guarantee for greater visibility and safety. The product I buy now for a few years on three bikes and would again. After several years is still very good reflects, if heavily soiled just enjoy it with a wet cloth and the parts are already as good as new! Of particular importance is that the reflector arrangement much faster than a bicycle is associated with two, three cats eyes.