Asymmetrical 4bolt 110BCD oval chainrings are designed for Shimano DuraAce 9000, Ultegra 6800, Shimano 5800 and other cranks with an asymmetric 4bolt 110BCD \n Oval rings help the rider to spin smoother and more efficiently \n Example: 32t is equivalent to 30t at dead spot and 34t at the power zone \n Narrowwide tooth profile keeps the chain snug, allowing you to leave the chain guide behind \n Designed in UK, manufactured in Poland