These large stones are designed to enable children to have sensory experiences by experimenting with the raised and indented shapes and patterns. Set of eight stones measure 3"L and include four raised/bumpy designs (circles, dots, wavy lines and a grid) and four indented/hollow designs (circles, lines, zigzags and a spiral). The set comes complete with a teacher’s guide full of exciting ideas for sensory play, messy play, printing and mark making. Ages 2 and up.