The Shimano Dura-Ace FC-R9200 chainring uses hollow forged technology to provide a significant weight loss while giving increased rigidity. This guarantees the optimum power transfer. 

SHIMANO 2/12-speed chainring for Dura Ace FC-R9200 crankset and Dura Ace FC-R9200-P cranks with powermeter. While the inner chainring is made of anodised aluminium, the outer chainring has been hollow-formed (Hollowglide) from anodised aluminium and carbon fibre-reinforced composite to save weight. This results in first-class stiffness values and high durability.

Compatibility (recommended):
• SHIMANO Dura Ace FC-R9200 2-/12-speed crank
• SHIMANO Dura Ace FC-R9200-P 2/12-speed powermeter crank