Shimano Dura Ace 9100 Bolt CoversYou are looking at chainring bolt covers for the Dura Ace 9100 crankset. They are designed to cover the gap left by non-Shimano issued chainrings equipped on Dura Ace cranks. They are manly for aesthetic purposes, making your crankset look slick and clean. | Shimano Dura Ace 9100 Bolt Covers Dura Ace 9100