In Jain tradition, Vajra means a diamond-thunderbolt weapon or extremely powerful, indestructible weapon.

It is often described in Jain stories as a weapon used by kings, chakravartins, or powerful celestial beings. Symbolically, vajra represents:

• great strength
• firmness
• indestructibility
• power to overcome obstacles

In Jain Dharma, however, the highest ideal is ahimsa, so such weapons are generally mentioned in scriptural stories and descriptions of royal life, not as objects to be admired for violence.

If you want, I can also explain Vajra as a symbol in Jainism or its use in Jain scriptures and stories.