Indradhanus is the bow of Indra, the king of Devas, in Hindu religion. It is also the name used to refer to rainbow. Legend has it that Indra’s bow resembles the rainbow. The bow was also used by Manmatha (Kamdev) to break the meditation of Shiva after the death of Goddess Sati.
It is believed that Indra gave the bow to Kamdev to bring back Shiva into the world. When Shiva entered into deep mediation after the death of Sati, there was imbalance in the world and creation came to a stand still without Shiva and Shakti. So Indra gave the bow to Kamadev to create passion in Shiva.
The God of love uses it to evoke love, affection, attachment and lust in men and women.