Function: 1. The lens itself is a T2 mount that can be mounted on a telescope to observe the moon, etc. With a standard adapter ring, it can be installed on the Nikon camera to shoot distant objects. 2. The hull is made of aluminum with a delicate texture. 3. Manual focus adjustment, multi-layer optical glass MC coating. 4. It has an extra long zoom of 420-800mm/16,5-31,5inch, and with a 2X teleconverter, the focal range is 840-1600mm/33,1-63inch. 5. Telephoto lenses are suitable for photographing distant scenery, wildlife, concerts, bird watching, etc. 6. An extremely powerful 2X teleconverter that can double the focal length or magnification. Specification: Weight: about 1058g / 37,3oz Options: black, white Lens parameters 420-800 mm: Item Type: Telephoto Lens Material: plastic aluminum alloy optical glass Focus mode: full manual focus adjustment Focal length: 420-800 mm / 16,5-31,5 inch Aperture: F / 8,3-16 Front filter diameter: 67mm / 2,6 inch Anti-shock function: none Applies to models: for camera with Nikon F mount (install standard adapter ring to use) 2X teleconverter parameters: Material: plastic aluminum alloy optical glass Coating: MC coating Interface: T2 mounting Magnification: 2X List of packages: 1 x Lens 1 x Front Lens Hood (Installed) 1 x Rear Lens Hood (Installed) 2 x Storage Bag 1 x Adapter Ring 1 x Key 1 x 2X teleconverter (lens cover installed)