Gold plated Gear, molded from from 2 clock cogs soldered, one on top of the other, 15 degrees twisted, making it thicker and 2 layered cog.

Pendant diameter is about 1.2 cm.
Gold-filled links chain or
Sterling Silver 2mm width curb chain.
Other chains and solid Gold might be available by request.
Sixth pic : Back side on a Silver chain.
Seventh pic : same same but from Silver :
https://www.galbarash.com/product-page/gb-gear
Unisex.