Made with natural stones. 2mm aquamarine, 5mm. Born in March. The meaning is marriage luck. Lapis lazuli 2mm, 3mm, 4mm. The meaning is good luck, for those born in September and December. The length is 80cm. Uses Opelet rubber. Wire is also possible. For those who wish to purchase: After liking the item, please feel free to let me know the length, wire or Opelet rubber, fittings (silver or gold), as surgical stainless steel fittings are available. Thank you for visiting.