ScaleSeven (S7) is a set of finescale model railway standards for 1:43.5 (7 mm scale) using true-to-prototype track and wheel standards. It is principally used to model British standard gauge (4 ft 8 1⁄2 in/1,435 mm), Irish Broad Gauge (5 ft 3 in/1,600 mm), or Great Western broad gauge
(7 ft 0 1⁄4 in/2,140 mm).