Canon EF 16-35mm F/2.8L III USM Lens
EF-Mount Lens/Full-Frame FormatAperture Range: f/2.8 to 22Three Aspherical & Two UD ElementsSubwavelength & Air Sphere CoatingsRing-Type Ultrasonic Motor AF SystemInternal Focus; Full-Time MF OverrideFluorine Coating on Exposed ElementsDust- and Water-Resistant ConstructionRounded 9-Blade Diaphragm