Continental is one of the oldest tire manufacturers.
Tread depth on bicycles isn't typically very critical, so no, it's intended for use on car/truck tires.
I'm thinking it's the adjuster from a hydraulic brake back plate.
The wheel with the notches is the adjuster you turn with the adjuster tool (through the little window on the back plate) and the rounded end of the shaft fits into a coupler on one of the brake shoes,
I have no clue as to the type or year of vehicle it may have been used on though.
Cool find......GL and HH