The Phase Fresnel element and three ED glass elements shrink this 500mm prime to a hand-holdable 2,445g, defying the bulk of typical super telephotos. Its Vibration Reduction system offers 4 stops of compensation with a dedicated Sport Mode for tracking erratic subjects, while the Silent Wave Motor delivers fast, quiet autofocus. This lens is best for wildlife and sports photographers using Nikon DSLRs who need extreme reach without a tripod.