Tamron 17-35mm f2.8-4 LD is an Auto Focus (AF) Wideangle Zoom 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 17 - 35mm. With a max aperture of f2.8, this lens is fast on wide end. The long end is also quite fast at f4.
Tamron 17-35mm f2.8-4 LD is not a weather sealed lens, so you have to be extra careful against rain and dust.