The Nikon AF-S Teleconverter TC-20E III doubles the effective focal length of select compatible NIKKOR lenses, offering an affordable and portable gateway to extend telephoto reach; ideal for sports shooting, wildlife, surveillance and more. The AF-S Teleconverter TC-20E III, is the worlds first teleconverter* to utilize an aspherical lens element (As of 10 December 2009). Nikon has released a new 2x AF-S teleconverter, the world's first to include an aspherical lens element. The AF-S Teleconverter TC-20E III is a completely new optical design designed to minimise its impact on image quality. When used with the 300mm F2.8 VR II lens launched today it would offer an effective 600mm reach at up to F5.6.