... : Open and Stud 3. Certificates:CCS, ABS, etc. u3 and u2 marine anchor chain Originally studs were added to the chain ... when chain is retrieved with a windlass.1. Material: U1, U2, U32.Certificate: CCS, ABS, LR, GL, DNV, NK, BV, KR ... and 3 stud & open link chain; marine anchor: Hall anchor, Japan Stockless Anchor, U.S.N Stockless Anchor and other marine ...