O Scale is a model railroading scale that represents a ratio of 1:48, meaning that one foot in real life equals ¼ inch on the model. This scale is popular among hobbyists for its balance between size and detail, allowing for intricate designs while still being manageable for home layouts. O Scale trains and accessories are often used in both indoor and outdoor settings. The O Scale is part of a broader classification of model train scales, which includes other sizes like HO Scale and N Scale. It is commonly associated with Lionel, a well-known manufacturer that has produced O Scale trains since the early 20th century.