Gonge Riverstones and Hilltops Combo Set is designed to improve coordination and balance. Jumping or stepping from stone to stone develops a child's confidence in their ability to judge distances. The side of each triangular block varies in steepness and difficulty, and the layout can be changed to make a pathway more or less challenging. Each stone has a non-slip rubber rim, which also protects indoor surfaces. Each set includes 11 stones in 6 colors: five measuring 14.96" x 14.56" x 3.35" , three measuring 10.23" x 10.23" x 1.77" , two measuring 16.14" x 16.14" x 6.69" and one measuring 16.92" x 16.92" x 10.23" .