DuraGrip The DuraGrip guitar picks are made from D'Addario 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. Unlike other standard delrin picks, DuraGrip features a unique, stamped checkerboard surface that gives superior grip while playing. Standard shape for comfortable playing Unique stamped grip surface Made from Duralin, a material known for its ideal combination of strength, grip, durability and abrasion resistance 4 X Extra Heavy Guage 7DBK7 1.5mm