Step-by-Step starts from a solid element in aluminum with a surface made of pleated elliptical modules, tilting towards the left or the right. Depending on the observer's perspective, charming games of light can be created. The basic modules can be installed individually or placed beside another one; modularity makes it suitable for both large spaces and smaller settings, since the compact overall dimensions (the radiator protrudes just 7.8 cm from the wall). Step-by-Step is available in hydraulic, electric or mixed versions and it heats up in two different ways: via radiation and through natural convection.