The seven etheric CHAKRAMS (whirls of energy) of the developed disciple stand in connection with and in relatin to the four "elements" and to several planes of creation. They are of special importance on the magic path and in the tantric tradition. Besides the seven big chakrams exists several other smaller Chakrams.

Wiki about Planes of Cosmology

Reference : Sri Y. Giri : The holy science ; A. Avalon : Mahanirvana Tantra ;