My son bought a 2003 Takara "World's Smallest Transformers" Optimus Prime figure used from a collectible store this weekend. Problem is that someone lost the world's smallest trailer somewhere along the way so we designed this one to replace it with.I printed it and then realized I messed up the hole. Instead of redoing it, I made a reducer but then I realized this is good because you can adjust it to any size you need to independent of the trailer then just put a dab of glue on it when it's perfect. The wheels are a really tight fit onto the axles which are made of the larger sized paper clips. Wheels and reducer are 100% fill, the trailer is 15-20%.