The BaristaPro Filter Baskets by IMS are designed especially to promote an even extraction and avoid channeling. To do this, they created a filter with a precise amount of holes - 661 to be exact - in the case of the double filter baskets or 269 for single shot baskets, that cover nearly the entirety of the basket. The diameter of the holes at 300 microns, is also larger than found in other similar filter baskets. Filter baskets from the Barista pro Nanotech series are coated with nano-quartz coating that eliminates any flavour being imparted by the metal and ensures that the basket will not discolour over time. The coating makes the baskets' life-span much longer while also making them very easy to clean. For use in 58mm Portafilters Specs: Body: Ø60mm Number of holes: 661 Capacity: 18 grams Material: AISI 304 stainless steel Made in Italy