NMJ, short for Norsk Modelljernbane AS, is a Norwegian specialist retailer serving model railway enthusiasts and model builders. With a stated passion for trains, the company offers its own NMJ ranges, including Superline, Topline and Skyline, alongside products from other manufacturers. Its catalogue features locomotives, powered railcars, passenger and freight cars, starter sets, track and track accessories in several scales. Customers can also find railway buildings, kits, scenery materials, trees, figures, vehicles and detailing supplies for creating layouts and dioramas.

The range extends to digital control systems, decoders, lighting, transformers and other electronics, as well as paints, weathering products, adhesives, tools, books, magazines and modelling components. NMJ highlights models inspired by Norwegian, Swedish, Danish and international railways, including European and US prototypes. Its online shop supports customer accounts and order tracking, and the site advertises a 30-day exchange period, fast delivery and free shipping on orders over NOK 3,000. NMJ also operates a 750-square-metre shop in Oslo, giving customers an in-person destination for railway modelling products.