Nikon TC-20E III 2189 AF-S Teleconverter Black Type: Converters & Adapters Format: FX DX FX in DX Crop Mode 35mm Film Camera Mount: Nikon F Compatibility: Nikon Lens Construction: 7 elements in 5 groups Specifications: Optical Conversion Factor: - 2.0x - Effectively doubles the focal length of the attached lens. AF-S (Silent Wave Motor): Yes Dimensions: 2.6 in. (66 mm) x 1.8 in. (46 mm) Weight: 11.06 oz. (330 g)