This model was designed for quick batch printing in PETG with a .6mm nozzle and .4mm layer height, but should work fine with .4mm nozzles too.
Tested when printed in PETG, it fits neatly but is still flexible enough for kids to clip and unclip.
Tested with (at least) Lidl & Brio tracks, should be compatible with other brands.
The author hasn't provided the model origin yet.
