The Yantra of Yoga of Heart is called Sri Hrdaya Yoga Yantra.
A yantra is a transformative device in the form of a geometrical diagram used in the practice of Tantra mainly to facilitate the meditative experience of merging with one’s own Heart or worship a deity in her/his essential visual form. The central element of each yantra is the mid-point known as the drop of life (bindu), or Heart (hrdaya). Everything emerges from Heart, exists by Heart and returns to Heart representing simultaneously the Source of Life and Whole of Existence.
The interpenetrating triangles symbolize the union of opposites (siva-sakty aikyam) as the truth of actuality flowering in all directions in the form of the eight-petaled lotus. The eight petals are matched by the eight corners created by the vibration of the basic square turning into two intersecting squares and housing eight essential seed mantras (om aim hrim srim om aim klim sauh). Above the yantra there is also the root mantra of Yoga of Heart (om srim sriyai namah), which is both Sri Lakshmi Devi Ma and Sri Lalita Devi Ma, or prosperity, auspiciousness and well-being for all.
Three basic colours white, red and black represent the three basic qualities of Mother Nature, that is intelligence, passion and endurance, respectively. Yellow and green represent Heaven and Earth, their mutual support and utter interdependence.