SRAM and Shimano compatible (7/8sp models have chamfered side plates for fast, smooth, quiet shifts). Delta hardened pins (no PC830), step riveting, and nickel-silver plating on upper-end models for extra durability. The higher the model number the greater the load capacity. 7/8sp PowerLink connector opens and closes without tools (1sp models use a 3-piece snap-lock connector). Save an additional 5+% on 25/box bulk chains with connectors (no aftermarket packaging)