The MIR-1V 2.8/37 is a high-performance prime lens with a 37mm focal length and a maximum aperture of f/2.8. - M42 mount (set to NF mount as it cannot be changed) - Model: MIR-1V 2.8/37 - Focal length: 37mm - Maximum aperture: f/2.8 - Accessories: Lens cap - Size: 65mm