Legendary Carl Zeiss optics, SteadyShot INSIDE image stabilization, High-grade metal body, Superior large-aperture performance, ED (Extra-low Dispersion) glass, Circular aperture, Dust and drip resistant design, Glass-molded aspherical lens elements, Optical design for top-end image quality, Quiet and smooth AF operation thanks to SSM, Carl Zeiss planar lens, SSM (Super Sonic wave Motor),