Developed to succeed the ef75 300mm f4 56 ii usm this compact lightweight high magnification telephoto zoom lens covers medium telephoto 75 mm to super telephoto 300 mm like the ef28 80mm f35 56 v usm it has a metal ring at the front of the zoom ring to give it an upscale image it incorporates a micro usm that enables quick and silent focusing for environment protection only lead free glass lens elements are used