Shimano Dura-Ace FC-7800 39 Tooth B-Type Chainring
Shimano OE replacement Dura Ace 7800 39T inner ring. Works perfectly when mated to a 7800 outer ring, but will work with any 130mm bolt crankset and 8, 9 or 10 speed drivetrain. Cut from straight block alloy, then profiled and polished to that high luster you expect from Dura-Ace. Not recommended for a single ring front(cross or fixed gear because of the tooth profiling).