Dorje and Drilbhu are the primary ritual tools of Tibetan Buddhism. They are always kept together and used in almost all the Tibetan ritual ceremony and chanting. The Dorje is held in the right hand and the Drilbhu in the left. They are made of bonze (some silver or gold coated).
Dorje (Tibetan), the diamond scepter or thunderbolt (Sankrit:Vajra) and the Drilbhu (Tibetan), the bell (Sankrit:ghanta) symbolize union of wisdom and compassion (method). Dorje represents the indestructible masculine principle of wisdom and Drilbhu represents feminine principles of the void and compassion. When they come together, an inner unity is achieved.
Dorje is the symbol of the 'diamond mind of enlightenment' so hard that cuts through all illusions and deceits and arrive at the clear light of truth. It is considered the ultimate spiritual weapon that is used to banish the forces of darkness, ignorance and disharmony with its power of lightning and clear truth.
Drilbhu represents the perfection of wisdom which perceives the primordial nature of emptiness. Its sound describes emptiness as it the sound arises from silence and dissolves back into silence (Mandala of creation and dissolution).
For procuring authentic Dorje and Drilbhu, we personally travelled to the Tibetan camp in Dehradun, north India where the Tibetan artists manufacture Dorje and Drilbhu in traditional Tibetan way. The gentleman who sold us the sets told us that the Dalai Lama during his visit to the camp advised them to keep their tradition alive in exile.