The Nanotech Portafilters are treated all-over with a special coating like the IMS Nano screens and baskets to get perfect non-stick properties and a much better durability compared to a Teflon® coating. This coating is a kind of a mineral coating (silica) which is food safe and resistant to most chemicals. The result is a cleaner cup and of course, the portafilter is much easier to clean, you can just rinse with water. The spouts are also nano coated.