SIGMA 20MM F/1.4 DG HSM ART LENS FOR NIKON F
F Mount Lens/FX FormatAperture Range: f/1.4 to f/16Two FLD Elements and Five SLD ElementsTwo Aspherical ElementsSuper Multi-Layer CoatingHyper Sonic AF Motor, Manual OverrideRounded 9-Blade DiaphragmTSC Material, Brass Bayonet MountBuilt-In Petal-Shaped Lens HoodCompatible with Sigma USB Dock