These are NOT Hollow or Plated. 1mm (020 gauge) - 1.6 - 4.0 grams (depending on Length). -We've Been Jewelry Wholesalers for 40 Years! 6mm (120 gauge) - 17.2 - 81.1 grams (depending on Length). 5mm (100 gauge) - 12.3 - 55.0 grams (depending on Length).