【Product Name】 SIGMA USB Dock UD-01 (Sigma USB Dock) for Nikon F mount 【Product Description】 Thank you for viewing. This is a listing for the SIGMA "USB Dock UD-01" for Nikon. This is a convenient accessory that allows you to connect compatible Sigma lenses to a computer to update firmware and perform **focus adjustment (AF micro-adjustment)**. Operation has been confirmed, and it can be used without any problems. The exterior has no noticeable scratches or dirt and is in generally clean condition. 【Included Items】 ・Main unit ・USB cable ・Original box / Instruction manual (※Only if included) ※All items shown in the photos are included. ***DSLRKIT Lens Focus Adjustment Card (Focus Chart) included (unused)*** This is for checking and adjusting the AF accuracy of SLR cameras and mirrorless cameras. When using the AF micro-adjustment function of the camera body, you can check the front-focus/back-focus tendency and achieve highly accurate focusing. Please consider this item as a used product. We will carefully package and ship it promptly. Thank you.