CP filters, also known as circular polarizers, are primarily used to eliminate unwanted reflections on non-metallic surfaces and enhance color saturation. They also intensify the blue of the sky, highlight white clouds, improve image clarity, and create a more expressive and vibrant picture overall. Additionally, they are often used for shooting through glass or water. Features: - Ideal for Sony G Master lenses - Compatible with wide-angle lenses - Slim design prevents vignetting - ZEISS T coating - Diameter: 72 mm.