King coconut is a variety of Coconut native to Sri Lanka where it is known as Thembili (Sinhala: තැඹිලි). Sweeter than regular coconuts, there are several sub varieties of "Thembili-the most common being the "red dwarf" (kaha thambili, commonly referred to as gon thambili). The other variety is "ran thambili", a smaller variety containing about forty nuts in a bunch. The king coconut tree is shorter than coconut trees, and are found commonly growing wild in many areas of the country.
This Aralu brew according to Sri Lankan ayurvedic practitioners (also known as veda mahattayas) has the necessary properties to "expel heat from the body" therefore resulting in a feeling of freshness.
The water of the king coconut is naturally sterile and therefore it is a good substitute for saline. In World War 2 both American and Japanese military doctors injected king coconut water into a patient’s veins instead of sterile glucose solutions.
Sri Lanka now exports packaged king coconut water.