The campagnolo hd link ultra narrow 10 speed is a section of chain with two joining links it boasts the hd link system which protects you from any risk of the chain not keeping traction at the closure point with 59mm special steel links for enhanced durability the chains also has ni ptfe anti friction treatment to reduce friction and allow for smoother quieter and more efficient pedalling lm features campagnolo hd link ultra narrow 10 speed section of chain with two joining