Zeal2 RB9X is a trail running shoe constructed with a sole made of one single moulded piece, to give the runner a unique combination of torsional stiffness and flexibility. Apart from the different sole, the shoe also has a redesigned heel cup; it is softer and lower than on many other shoes, which gives reduced pressure at the Achilles tendon. Zeal has a low sole profile that provides excellent ground contact and the outer sole has a rough texture with studs that give great traction on soft surfaces. The shoe's upper is manufactured from a lightweight material that does not pick up water, which means the wet weight is almost the same as the dry weight. This is a shoe that is equally suitable for trail running as for swimruns.