Rokinon 24mm f1.4 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 24mm. Providing a max aperture of f1.4 at 24mm, this lens is very fast.
Rokinon 24mm f1.4 is not a weather sealed lens, so you have to be extra careful against rain and dust.