After already having invented the first square wheel mechanism in 2010, Maurice Lacroix has now created the Masterpiece Roue Carrée Seconde, which is all about the seconds display. The seconds are indicated by a square wheel that is driven by an adjacent cloverleaf-shaped wheel. The development of this mechanism required a large number of calculations and tests. The biggest challenge lay in defining the teeth shapes in order to ensure constant power transmission through the gear. The wheels mesh with the same smooth movement as conventional round wheels.