B+W Smart Pro Neutral Density Graduated Circular Polarizer Circular polarizing filter for an iPhone, iPad, smartphone or tablet PC Small magnetic ring goes around the lens on your device; filter can be attached and aligned Works on all small camera lenses with a maximum diameter of 8mm Eliminates reflections and provides saturated, intense colors. Improved contrast ratio No app/software can mimic the effect created by this filter and eliminates reflections Provides saturated & intense colors; improved contrast ratio Includes: Smart-Pro Circular Polarizer, magnetic ring and carrying case