These are miniature components, crafted from diecast metal, designed for assembly or replacement in model vehicles at a specific dimensional ratio. For instance, a steering wheel, tire, or engine block intended for a model car that is one-eighteenth the size of the real vehicle falls into this category.
The availability and use of these items allow hobbyists and collectors to restore damaged models, customize existing ones, or even build replicas from scratch. They contribute significantly to the realism and detail of the finished product. The practice also has historical roots, tracing back to the increasing popularity of model cars and the desire for greater accuracy in representing real-world vehicles.