Hardened steel with 10mm thick links. Large internal link size (16 x 50mm) for use with large shackles. Yellow passivated for increased corrosion resistance. Hard-wearing sleeve to reduce impact damage. Hardened steel with 10mm thick links. Large internal link size (16 x 50mm) for use with large shackles. Yellow passivated for increased corrosion resistance. Hard-wearing sleeve to reduce impact damage.