The guitarra portuguesa is a plucked string instrument with twelve steel strings, strung in six courses of two strings. It is one of the few musical instruments that still uses watch-key or Preston tuners. There are two distinct Portuguese guitar models: the Lisboa and the Coimbra. The differences between the two models are the scale length, body measurements, and other finer construction details. Overall, the Coimbra model is of simpler construction than the Lisboa model. Visually and most distinctively, the Lisboa model can easily be differentiated from the Coimbra model by its larger soundboard and the scroll ornament (caracois – snail) that usually adorns the tuning machine, in place of Coimbra’s teardrop-shaped (lagrima) motif.