According to Nikon :
The NIKKOR Z 400mm f/4.5 VR S is a super-telephoto 400-mm lens that offers both superior sharpness and clarity, in a compact size with light weight. Handheld shooting is easy with the lightest*1 weight in its class, approximately 1,160 g (excluding tripod collar), and a total length of approximately 234.5 mm, providing superior agility and reducing fatigue over extended shooting sessions of wildlife including birds, and sports photography. Use of the Z TELECONVERTER TC-1.4x or the Z TELECONVERTER TC-2.0x extends the focal length of this prime lens to 560 mm or 800 mm, respectively*2, expanding its power of expression with the ability to bring distant subjects even closer, and dynamic rendering. In addition, the lens offers excellent balance by shifting the center of gravity closer to the camera for more stable operation during handheld shooting.