Kamandalu is a coconut shell bowl held by Lord Brahma and several other deities in Hindu pantheon. The Kamandalu holds water. Symbolically Kamandalu in Lord Brahma’s hands suggest that water is life and is the physical element that caused the whole creation to exist.
The coconut shell bowl or Kamandalu is also used by saints to carry water from the holy rivers, which are then used for pujas and rituals.
Earlier the Kamandalu was made using coconut shell but nowadays the Kamandalu is available in copper, silver and other metals.
Kamandalu is mainly associated with Brahma as he is the Hindu god associated with creation. Lord Shiva and Lord Vishnu are not depicted with a Kamandalu in their usual form.
Nowadays several other deities like Lord Vishwakarma and some Goddesses are also depicted with Kamandalu. In some cases Kamandalu symbolizes a holy person or a person who is undergoing tapas or austerity.
The main symbolism associated with Kamandalu is that of water and it is related to creation and existence.