The D'Addario Duralin pick line is vast, featuring various shapes and grip options. The Duralin Assorted Shapes pack take your preferred gauge and offers 2 of every style which includes standard shape, wide shape, Black Ice, Precision, and Duragrip. Available in 3 gauges. Duralin (also known as Acetyl or Delrin) is a unique material with an extraordinary combination of strength, stiffness, dimensional stability, fatigue resistance and low friction. Normally used as a replacement for metal bushings and bearings in industrial applications, this extremely durable polymer is ideal for picks. Duralin picks are known for their bright "licking sound when hitting strings and are preferred by many soloists for their clear articulation on fast single note passages.