Pentax D FA 28-105mm F3.5-5.6ED DC WR HD Lens (Black) Built-in DC motor to assure smooth, quiet, high-speed autofocus operation Diaphragm blades: 9(rounded).HD (High Definition) - Treated with state-of-the-art HD technology; a high grade, multi-layer coating, allowing the user to capture crisp, high-contrast images free of flare and ghosting, even under demanding lighting conditions ED (Extra-Low Dispersion) glass lens elements deliver clear, high resolution imagery with outstanding edge-to-edge sharpness throughout the entire zoom range WR (Weather Resistant) - Designed with eight specially designed seals to prevent intrusion of water