• The first release in the "atx-i" series that has been renewed to pick-up, look, performance, and specifications from the best selling AT-X PRO series • The only APS-C format lens for DSLR lens with an open F value of F2.8 (As of September 2019, Kenko Tokina research) • 2 aspherical lenses and 2 ultra-low dispersion glass for high performance demands for both stills and video • Uses a WR coat (water repellent/oleophobic coat) that repels water and oil so you don't miss a chance to take pictures • The "One-Touch Focus Clutch" allows you to switch between focus modes at all times. Adopts an inner zoom system that does not change the length of the lens when zoom or focusing