Feature●The first eco-friendly ukulele string, exclusively from Aquila●Plant-derived from castor oil?100% natural components●Manufacturing process reduces CO2 emissions more than 50%●Smooth playing surface, warm and mellow tone●To learn more, please see our Product Description belowDescription Bionylon is the worlds first eco-friendly synthetic string and is available only from Aquila! Bionylon is 100% plant derived (castor oil) and allows for a reduction of more than 50% of carbon dioxide emissions during the manufacturing process.