Wikipedia
Manguerito
The manguerito (or charanguito manguero) is a stringed instrument, a variant of the Andean charango, invented by Ernesto Cavour from La Paz, Bolivia. The instrument was intended to be small enough to be carried and hidden in one's sleeves , thus the term. It has 7 nylon strings in 5 courses and is tuned D4, G4, B4 B3, E4, B4 B4.