Product Description Cokin Varicolor Polarizer Filters take on different colors when rotated vertical to horizontal (or horiz. to vert.). You will discover a whole palette of unexpected and unusual shades which will enhance reality. They are available in five color pairs. Each will rotate to either color and all combinations between Amazon.com Cokin filters were invented by professional photographer Jean Coquin. By using square filters like Cokin's, which fit into a holder and are attached to a lens via an adapter ring, the photographer has a number of immediate advantages. There is no need to duplicate filters to fit different size lenses, up to three filters can be used at once to create unique effects, and the photographer has control over the positioning of the effect on the photograph.