The centre of the vajra is spherical—Dharmata—the space of reality (Chö-nyi – chos nyid). In the Aro Lineage the nine-pronged dorje (tse gu – rTse dGu) is usually used, as it was the implement of the Nyingma lineages in the first spread of Buddhism in Tibet. Generally the nine prongs represent the nine yanas – but in the Aro gTér lineage the nine prongs represent: the nine bardos; the nine skies; the nine mélong sem’dzin of Dzogchen long-dé; the ‘Nine Songs of the Owl-headed Dakini’; the ‘Nine Grim Weapons’; and, the ‘Nine Grim Garments’. Here we see two crossed five pronged dorjes, representing the five Buddha families, the five wisdoms (yeshé nga – ye shes lNga), and the five elements (kham-nga – khams lNga). The two sets of five prongs together symbolise the five dakas and five dakinis (khandro pawo dé-nga – mKha’ ’gro dPa bo sDe lNga). Combined, they represent the ten perfections, the ten phases of realisation of a changchub Sempa (byang chub sems dPa – Sanskrit bodhisattva); and the ten directions (chog-çu – phyog bCu).