ANCHOR CHAIN-Stud Link Anchor Chain Material: Steel or Stainless steel. Size from 12.50mm to 107mm. U2, U3 Grade. Class Certificate: ABS, LR, BV, DNV, GL, NK, KR, IRS and CCS We supply all kinds of U2&U3 Stud Link Anchor Chain and can provide connectivity solutions, such as Open Link Anchor Chain, Kenter Shackle and End Shackle, all of these products we also supplied together.