The Thiene is made in Japan by O-ring chain which does not need oiling. The sprocket is made of steel with a "unichrome plated" finish.It is 10 times more durable than aluminum. Thien size is 530-110 links.Please use it after cutting it because the stock is 104 links. This Thien is reinforced O-ring chain, so the pin is thicker and stronger than usual, and it is coated with black to prevent from stretching and rusting.