Sigma 2x EX DG APO Tele-Converter AF for Nikon AF Cameras Sigma 2x EX DG APO Tele-Converter - Front & Rear Lens Caps - Soft Case - Sigma 1 Year North and South America Limited Warranty (3 Year USA Extended Warranty for a Total of 4 Years from Date of Purchase) Construction: 5 Groups /6 Elements Angle of view: F stop range: Closest Focusing Distance: