Featuring a high-performance optical design, a quiet high-speed SSM (Super Sonic Wave Motor) auto-focus drive system with enhanced object tracking, & an anti-glare nano AR coating, the SAL300F28G2 super telephoto Sony G lens delivers both high contrast & beautiful bokeh effects at levels far surpassing those of existing 300 mm f/2.8 lenses. Take advantage of fast internal focusing & two DMF (direct manual focus) modes for tack-sharp images in any situation. Designed with outdoor use in mind, the front & back of the unit as well as the area around the focus ring are specially constructed to help prevent water penetration.