1:24 scale is a size for automobile models such as injection-molded plastic model kits or metal die-cast toys, which are built and collected by both children and adults. 1:24 means that a unit of measurement, such as one inch or one centimeter, on the model represents 24 units on the actual object. An example would be one inch of length on a model automobile would represent 24 inches on the real vehicle. Primarily automobile models are made in this scale, with a few examples of tractor trailers and other larger equipment. In the United States there is a very minor variation of the 1:24 scale, where many automobile plastic model kits are scaled at 1:25.