Paper filters designed for cone shaped drippers such as the Cafec Flower Dripper, Hario V60, etc.
These Light Roast Filters are designed with a smooth surface inside and crêped surface outside. The paper is also of a higher density to "normal" filters. The theory here is that the density of the paper and smooth inner surface help to regulate/slow the flow and catch more of the fine particles resulting in a higher extraction and cleaner more juicy result in the cup. This also means they are designed to brew a little slower than other filters.