This is the one of 17 (don’t ask why) tread/gears fabricated for the Dalek stair climber assembly. Turns out they learned to levitate prior to the prototype being finished, so they ended up taking up space in the corner of a garage somewhere until someone got the idea they could be fashioned into combination retro bottle opener/shoelace irons. Despicable Escape, Dark Gray, XXL
Despicable Escape, Dark Gray, XXL