Tokina internal focus AF lens with a focal length of 10-17mm. NIKON f-mount DX format. - Model: Tokina 10-17mm - Focal Length: 10-17mm - Internal Focus: Yes - Minimum Focusing Distance: 0.2m - Maximum Aperture: f/3.5-4.5 Thank you for viewing. Focal Length (Wide): 10mm Focal Length (Telephoto): ~18mm Open F-value: 3.5-4.5 Other Features: Front lens cap included, Rear lens cap included The mount is NIKON f-mount. The format is DX format. There is no mold or clouding in the optical system. AF and AE are working. The distance ring lacks torque and feels a bit loose, but this does not affect use. NIKON f-mount, DX format.