Filter paper for the top of the Cafelat Robot Filter Basket - just above the coffee. Using a filter paper on the top of the coffee bed vastly increases the cleanliness as you pour in the water to the basket, and it prevents coffee residue & build up in the Robot Piston Seal. These are custom sized to fit exactly in the top of the Robot Basket, 57.45mm in diameter, and they also fit very well in the bottom of a standard 58mm Portafilter basket (particularly nicely in an IMS Competition basket!) We have tested this 'top' paper in the bottom of various baskets (a nominal '58' is usually about 58.4mm or so at the top of the basket, and they taper toward a rounded bottom edge) Made from standard white coffee crepe filter paper, made in Japan by Cafec, and cut in the USA. 90pc in the package.