Nickel plated inside and out, our PC-991 Power Chain II looks good enough to wear. But that would be a serious waste of performance. The nickel plating is there for faster, more accurate shifting in all conditions, not blingage. Exclusive PowerLink™, technology closes the chain (and the loop).The Hollow Pin PC 991 chain features a special hollow rivet pin to reduce weight yet still retain its powerful push-pin strength.