The idea behind the product is ingenious, the price-performance ratio is wrong! \ R \ nThe stated service life is far exaggerated. Maybe you can get this far with smooth surfaces (90 to 120 m²), with normally rusted steel surfaces with paint / paint residues, heavy wear occurs very quickly and the performance drops rapidly. A shame! \ R \ nSince the material and manufacturing costs for the product are estimated to be rather low, a price around 50% of the current retail price would be justified.