Five rainbow infinity pins. My friend makes them as an autism pride symbol, and had sent me one. The cub immediately adopted it for his bulldozer shirt because it looks like the "everything" boost in Mario Kart and he wanted his bulldozer to be a kart.
Cue tantrum when we lost it.
My kind friend is attempting to ensure there is no repeat of the tantrum because I will have plenty on hand. Only problem is the cub was there when the package arrived, and I dropped it and all five spilled out, so he saw how many extras there were.
Now his bulldozer has five boosts all at the same time.