The concept of the object is very attractive. The device is beautiful, about 70 cm high with big eyepiece, bright white, design side all is well studied. Getting started is easy. The cache it is deposited are three parts, two filters and a grid. Protective plastic is removed and replace it. And you plug it starts. 3 speeds: normal, hard and operation for the night, less noisy, even if the machine really works without much noise. 3 color codes: red = bad quality of air, purple = average air quality, and blue = good. There is also an indicator to change filters, but I'm not there yet. And it is this last point that made me remove a star. Filters are to change, I do not know how often or at what price. On an equivalent model 70. To watch for these filters. The effect on the air as we read is not at all obvious, but we have to trust the technology!