This is a 13th century sandstone pranala (water spout) from Kerala. It is a duct emerging from the mask-like face of a kirtimukha (face of glory). This architectural fragment of a temple would have served the purpose of carrying the water and milk from the ritualistic libation of the deity in the sanctum outside. It is generally found in Shiva, Murugan and Durga temples but generally not in Vishnu temples although there are some exceptions. Devotees usually touch the pranala, scooping and drinking a few droplets from the stone basin below.