Digital Nc C-PL (Circular Polarizer) Multicoated | Multithreaded Glass Filter (72mm) For Sigma 18-35mm F1.8 DC HSM Between 2.3 and 2.8 (approx. +1.3 stops) Rugged Metal Filter Ring (Black Finish) | Heat Treated Glass Slim Design Minimizes Vignetting Multicoated Designed For Video Or Photography | Multithreaded For Mouning Lenses Or Filters On Top