The thunderbolt or diamond that destroy all kinds of ignorance and itself is indestructible . The vajra is symbol of Indra also. In tantric rituals , the vajra symbolised the male principle which represents method in the right hand and the bell symbolised the female principle , is held in the left . Their interaction leads to enlightement . Also the Dorje or Vajra represents the “Upaya” or method .Tibetans name Vajra as “Dorje”.