Sorry, but the Zoom Gear (56350) does not work. The diameter is too small :no (but maybe you meant the Zoom Gear for the AF-S Zoom Nikkor ED 17-35mm f:2,8D).
I'm owning both, the SIGMA 17-70mm f:2,8-4,5 DC Macro and the AF Zoom Nikkor ED 18-35mm f:3,5-4,5D.
I adapted the Focus Gear (56140)...