GraviTrax Junior is suitable for children aged 3 and up. Boys and girls build their own marble run worlds, which can be freely decorated to create unique themed worlds. The Hammer action element, like all other construction parts of the interactive marble run system, is made of wood-bioplastic. The Hammer adds even more speed to the track – for endless building fun. GraviTrax Junior is an interactive marble run system for children aged 3 and up. - Elements add more variety to the marble run - The highlight of any track - Can be combined with all Junior Starter Sets - Elements add more variety to the marble run - The highlight of any track - Can be combined with all Junior Starter Sets GraviTrax Junior is suitable for children aged 3 and up. Boys and girls build their own marble run worlds, which can be freely decorated to create unique themed worlds. The Hammer action element, like all other construction parts of the interactive marble run system, is made of wood-bioplastic. The Hammer adds even more speed to the track – for endless building fun. GraviTrax Junior is an interactive marble run system for children aged 3 and up. Children can build their own marble run world to their heart's content and decorate it with all sorts of different theme sets. Creative building and playing fun are combined. age 3-7 years packaging size 11x11x6cm not suitable for children under 36 months