This is a Yin Yang Mandala Crystal Grid made out of birch wood. These are made to order. You may choose between 4, 6, 8, 10 or 12 inches in diameter. All grids are 1/4 inch thick. Crystal grid and healing sets are groups of stones that go together for a purpose. Sets of crystals and stones are used for ritual magickal or spiritual crystal healing purposes or with Reiki-Seichim energy work for healing.