Nauticam SC816-Z Zoom Gear ~for Sigma 8-16mm F4.5-5.6 DC HSM
Zoom gears allow access to the mechanical zoom function of supported lenses. Use of this gear may require the use of additional port extensions or adapters. Check the Port Chart for more details. This zoom gear is for the Sigma 8-16mm F4.5-5.6 DC HSM lens.