OO gauge is a popular model railway scale that represents a ratio of 1:76.2, meaning that 1 inch on the model equals 76.2 inches in real life. This scale is widely used in the United Kingdom and is favored for its balance between size and detail, making it accessible for both beginners and experienced hobbyists. The track gauge for OO gauge is 16.5 mm, which is equivalent to 0.65 inches. This allows for a variety of locomotives and rolling stock to be produced, including models of famous trains like the British Railways steam locomotives. The scale's popularity has led to a vast range of accessories and scenery options available for enthusiasts.