The Sigma USB Dock for Canon works in conjunction with Sigma Optimization Pro software in order to connect a photographers lens to their personal computer to update firmware, calibrate the lens and other customizations such as the focus parameter.
For the Sports category, changes can be made to: Autofocus speed, focus limiters, manual focus override and optical stabilization functionality.
Updating the firmware can be done via the internet. Sigma Photo Pro is available for Mac and PC computers. Focus Settings: 4 Categories of customization for fixed focal length. 16 Categories of customization for zoom lenses (4 options for focal length) x (4 options for shooting distance).
For Sports Line: AF Speed: 3 adjustment modes Sigma USB Dock for Canon
Focus Limiter: Customize auto focus range. OS: 3 adjustment modes. The Sigma Optimization Pro can be downloaded at the Sigma Global Vision site.