Telephoto Zoom Lens, 420-800mm F/8.3-16 All Manual Focus Telephoto Lens T2 Mount for Canon, Sony/Minolta, Nikon, Pentax, and Other DSLR Cameras

Great value for your money, very easy to use. The lense adapter did not fit my camera but got one that did quite cheap.....

Although the telephoto lens with an adapter is made for Nikon D3100 I get the message "Lens not attached". Now, I may be thick or something, I do have a stroke, but there is a lens poking out of the camera body! As I say, the telephoto lens is not what its designed to do.