Voigtlander 40mm F2 SL II is a Manual Focus (MF) Standard 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 40mm. Providing a max aperture of f2 at 40mm, this lens is very fast.
Voigtlander 40mm F2 SL II is not a weather sealed lens, so you have to be extra careful against rain and dust.