Canon 24-85mm f3.5-4.5 USM is an Auto Focus (AF) Standard 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 24 - 85mm. With a max aperture of f3.5 at 24mm, we can not consider this lens fast on wide end and neither at tele end with its f4.5.
Canon 24-85mm f3.5-4.5 USM is not a weather sealed lens, so you have to be extra careful against rain and dust.