The koteka is normally made from a dried-out gourd, Lagenaria siceraria, although unrelated species such as pitcher-plant (Nepenthes mirabilis) are also used.

For example, Yali men favour long, thin kotekas that help hold up the multiple rattan hoops worn around their waists, whereas Lani men wear double gourds held up with strips of cloth and use the space between the two gourds for carrying small items such as money and tobacco.

For Hubula (Dani) people of Baliem Valley, the shape of horim is associated with the social status of the wearer.

Curves can be made in it by the use of string to restrain its growth in whatever direction the grower wishes; the koteka can be quite elaborately shaped in this manner.

The term koteka is used as a self-proclaimed name by Assembly of Koteka Tribes (DeMMak) organization who claimed to represent Koteka people, a union of seven major koteka-wearing tribes in the central and southern highlands of Papua; namely Lani, Mee, Amungme, Kamoro,[citation needed] Yali, Damal, and Moni with other sub-tribes such as Nggem, Walak, Hubla, Kimyal, Momuna,[citation needed] Ngalik.

In 1971–1972, the Indonesian New Order government launched "Operasi Koteka" ("Operation Penis Gourd") which consisted primarily of trying to encourage the people to wear shorts and shirts because such clothes were considered more "modern.

They are usually made out of gourds or woven fibers and decorated with feathers, beads, cowry shells, and small metal ornaments.