Yellow Door 8-Piece Sensory StonesThese large tactile stones are designed to enable children to share in sensory experiences by experimenting with the raised and indented shapes and patterns. The set of eight stones includes four raised bumpy designs (circles, dots, wavy lines and a grid) and four indented hollow designs (circles, lines, zigzags and a spiral). The stones measure 3". The set comes complete with a teacher's guide full of exciting ideas for sensory play, messy play and