Canon EF 24-105mm f/3.5-5.6 IS STM Lens Optical Image Stabilizer provides up to four shutter speed stops of correction. Focal Length & Maximum Aperture 24-105mm 1:3.5-5.6 New 7-group zoom optics allows for a conveniently compact design and outstanding optical performance Two aspheric lenses plus a UD lens combine to provide high-quality results for both still images and movies Circular aperture (7 blades) delivers beautiful, soft backgrounds Inner focusing system, high-speed CPU and improved AF algorithm allow high-speed autofocus