Nikon TC-17E II is the first teleconverter to offer 1.7x performance. Designed exclusively for use with AF-S and AF-I lenses, the AF-S Teleconverter TC-17E II completes the Nikon lineup of 1.4x, 1.7x, and 2.0x compact teleconverters.With dimensions of just 66 x 31.5mm (2.6 x 1.2 in.) and a weight of only 250g (8.8oz.)(approx.), the AF-S Teleconverter TC-17E II allows focal length to be extended by a factor of 1.7 times while retaining a sense of overall comfort in the hand. Many such teleconverters can also have a detrimental effect on the speed of the lens, however the AF-S Teleconverter TC-17E II makes available f-stops only 1.5 stops slower.The AF-S Teleconverter TC-17E II also has the ability to communicate with the signals from most lenses. Furthermore, it supports the convenient Nikon Vibration Reduction (VR) function, has a design that is consistent with the current TC-14EII and TC-20EII, and Eco-Glass is also used.This product is designed for AF-I & AF-S Lenses only.