NW40 undergoes the same manufacturing processes as Nature Works Hi-Tech Glass Filter Media, so in terms of performance it is the same. In other words, it has the same particle size distribution curve  (0,6–1,2 mm) and the same retention capacity and savings in energy and water.  The difference between Nature Works Hi-Tech Glass Filter Media lies in the type of glass used in production. While the former uses only virgin clear glass (mostly window offcuts), NW40 uses post-consumer recycled glass from bottles. It is subjected to advanced optical and mechanical separation processes to clean it and obtain a very high-quality media—though, of course, not with the same level of hygiene at source as Nature Works Hi-Tech Glass Filter Media.