This thing was made with Tinkercad. Edit it online https://tinkercad.com/things/kigMlJ3Jrhk
This is a helper tool for gluing slot tires on rims with 3mm axles.
Most 1/24 scale slotcars have it, and some 1/32 too (Scaleauto Procomp Tires).
Its is for gluing foam rubber tires in a water bath.
Up to 12 tires can be glued at once.