50pcs Black Satin Silk Necklace Cord 2.0mm/20'' with 2'' Extension Chain Lead&nickel Free The satin silk cord we used is silky and smooth feels, flexible and durable to use. The satin cord we use is shiny, strength, acid-proof, wear-resistant, not absorbing the sweat and will not fade. All the metal parts are lead and nickel free LENGTH - Each necklace cord size are 20/ 50.0cm length (not include the 2'' of extension chain), you can use the lobster claw clasp to adjust the length Ready-made necklace so that you can add pendants, charms or other jewelry findings