Sigma is updating two of its Nikon mount lense

The two redesigned Sigma lenses are the 18-50mm F/3,5-5,6 DC HSM with Nikon mount and the telezoom 55-200mm F/4-5,6 DC HSM, still with the Nikon mount. The comfort improvement of such a supersonic driven autofcus sustem is really important and with this lens update, Nikon is keeping up with competitors.