The coffee filters were specially made for the Moccamaster machines but can also be used for all other filter machines. The filter paper is size No. 4 and has been bleached in an environmentally friendly way using oxygen. The Dutch company Moccamaster only uses paper from responsible sources that is FSC® certified. The filter papers from Moccamaster guarantee you a perfect development of the aroma and perfect your very personal coffee experience with your Moccamaster coffee machine.