Sigma AFL-950 46mm EX DG Circular Polarizer Filter Circular polarizing filter designed to filter light rays through camera lens Removes reflections and increases color saturation without affecting color balance Ideal for nature, travel, and outdoor photography; high-quality glass construction Specifically designed for use with auto-focus SLR cameras; 46mm thread size Filter factor between 2.3 and 2.8 (approximately +1.3 stops); 1-year warranty