As with the classic OS-MED BLK, we use high quality fluorocarbon material. Durable and stable material keeps sound stable even after long periods of use. It is also resistant to environmental changes such as temperature changes and humidity changes, especially in outdoor conditions. The basic concept of ORCAS is "Making the character of the Ukulele body more without being too strong to emphasize the character of the string, but the same as OS-MED has been saud-tuned in a slightly brighter direction. Features characters that make you feel more powerful with Attacky. ■Type=Soprano, Concert ■Gauge=Medium ■Tuning=Regular 1st:0.49mm (0.019inch) 2nd:0.70mm (0.027inch) 3rd:0.76mm (0.031inch) 4th: 0.55mm (0.022inch)