Leading racing teams in the road and off-road sports rely on the technology of DID. The 520NZ is a reinforced standard chain with seamless castors (made from Round material, therefore no weak points). In addition, for the 520NZ a special method (SDH) rivets, which have a high surface hardness respectively. 1x Black DID 520 NZ Series Chain. Product Type: Chain and Sprocket Kit.Plate Thickness - Inner: 2.2mm. Plate Thickness - Outer: 2.2mm. Tensile Strength (kN): 36.5kN. Weight per 100 links: 1.6kg. You can send us a message by using the "Questions and answers" section towards the bottom of the page.