Canon 200mm f2L IS USM is an Auto Focus (AF) Telephoto Prime lens with 35mm FF max sensor coverage. When mounted on a 35mm FF sensor camera, it will give you an FF equivalent focal range of 200mm. Providing a max aperture of f2 at 200mm, this lens is very fast.
This lens features on optical image stabilization which helps capturing sharper images at lower shutter speeds. Canon 200mm f2L IS USM is weather sealed which makes it an ideal lens for outdoor use, especially when coupled with a weather sealed camera body.