The new Flat less tire. After 10 years, we have thoroughlyoverhauled the Marathon Plus. The only true flat less tire gets a new, dynamic profile and boasts many internal improvements: Rolling resistance. The patented, 5 mm thick SmartGuard layer, when compared to all generic products, has a significant advantage in rolling resistance. We further extended its lead in the latest version. Recycling. Also in the SmartGuard, we now use a proportion of recycled rubber from old latex products. Anti aging side wall. It now lasts much longer before deveolping unsightly cracks when subjected to use with too low air pressure.