The Olympus M.ZUIKO DIGITAL ED 40-150mm f/2.8 PRO Lens - Black V315050BU000 is a specially designed lens with premium metal construction that makes the inside of the lens body dust free and splash-proof. This sharp telephoto zoom lens has a 35mm equivalent focal length of 80-300mm. Perfect for micro four thirds, it comes with a fast constant f/2.8 aperture. Offering an incredible friction-free fast performance, the Dual Voice Coil Motor autofocus system is also effectively very quiet with two separate lens groups controlled by linear drive motor. Featuring 16 elements in 10 groups, the extra-low dispersion aspherical, super extra-low dispersion, extra-low dispersion, and a high refractive index offers better control over aberrations and distortion.