All Kogi men receive a 'poporo' when they come of age. The 'poporo' is a small, hollow gourd that is filled with 'lima,' a type of powder that is made by heating and crushing shells to produce lime. The men also continuously chew coca leaves, a tradition followed by many indigenous tribes to connect them to the natural world. As they chew the coca leaves, they suck on the lime powder in their poporos, which they extract with a stick, and rub the mixture on the gourd with the stick to form a hardened layer or crust. The size of this layer depends on the maturity and the age of the Kogi man..