This is Torus Yantra crystal #2 grid made out of Birchwood. These are 10 inches in diameter and 1/4" thick. This is just for the grid, stones much be purchased separately.
In geometry, a torus (plural tori) is a surface of revolution generated by revolving a circle in three-dimensional space about an axis coplanar with the circle. ... Real-world examples of toroidal objects include inner tubes.
The Torus is the aura at the sacred geometrical level which gives and receives energy. The Aura is the connection points of all your chakras together which creates the vortex energy. the balance of yin/yang
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. Some are generalized and others have specific purposes.