Albinar Nikon Lens to M4/3 Camera Body Adapter with Speed Booster Focal Reducer Glass Focal Reducer Speed Booster Adapter Made of metal structure and excellent Muli-coated optical glass Reduces the focal length (by 0.72X wider) Effectively increases the maximum aperture of the lens by 1 stop Front and Rear Cap included for protecting this Focal Reducer Speed Booster Lens Turbo