Sigma USB Dock (UD-01NA) for Nikon F-Mount

(USED - Like New Condition) The Sigma USB Dock (UD-01NA) for Nikon F-Mount is an essential accessory that connects your DSLR lenses directly to a computer to update firmware and customize internal settings. By pairing the dock with the free Sigma Optimization Pro software, photographers can fine-tune autofocus performance and correct front- or back-focusing issues at home without sending the lens to a service center.