"A truly versatile zoom lens with its large aperture of f/2 that inherits the consistent high image quality from prime lenses across its focal length. Delivering highest standards of descriptive performance at wide open aperture truly provides you the convenience of performing the work equivalent to a few prime lenses. The bright aperture of f/2 makes this RF28-70mm f/2L USM ideal for those seeking for low-light capability and amazing background separation. RF28-70mm f/2L USM features an additional control ring on the barrel that could be customised to control exposure settings; shutter speed, aperture, ISO and exposure compensation, effectively providing better control especially while shooting through the Electronic View Finder. The control ring has a tactile, easily distinguished surface and features a clicking mechanism that provides tangible feedback during adjustment. Filter Size: 95mm Max aperture: f/2 Additional Control Ring With ring USM motor Dust and Drip Resistant "