Nikon PC Nikkor 19mm F4E ED is a Manual Focus (MF) Wideangle 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 19mm. With a max aperture of f4 at 19mm, this is a moderately fast lens.
Nikon PC Nikkor 19mm F4E ED is weather sealed which makes it an ideal lens for outdoor use, especially when coupled with a weather sealed camera body.