gear mesh addon

Wondering ? Looking in the preference panel for the add on for gears. Not there. I am modeling the tuning machine for a classical guitar and need to model the spur and worm gears. Been working with blender only a couple of months and a lot to learn. So I guess my questions are, how to install the script as add on in the preference panel, or some direction in how to run a script. Been searching for answers, must be missing something. Tried several times to model them using the spin and screw commands. The spur gear was quite easy but the worm is eluding me. To get them to mesh :spin:. Any help is much appreciated.

Enable the “Extra Objects” addon.
Hope that helps:eyebrowlift:

Thanks Karakasimov. Would never have found that.