SIGMA USB Dock UD-01 (for Canon). The SIGMA USB DOCK is a lens accessory exclusively for the Contemporary, Art, and Sports lines, allowing users to connect to a PC via USB cable to update lens firmware and adjust focus positions. This is an adjustment dock compatible with Sigma lenses for Canon EF mount. No instruction manual or box included. The two items in the photos are all that's included. This is a used item. There are minor scratches and dirt. Please understand this before considering a purchase.