With several years of development and working closely with professional teams, you can expect extreme accuracy from Shimano's first fully integrated power meter, HollowTech II 12-speed Dura-Ace chainset

• Accurately calibrated strain gauges are integrated inside both left and right crank arms, which provides a stable measurement system through rotation from both sides for exact data
• +/-2% accuracy of strain gauge measured power
• Bluetooth and ANT+ with wireless firmware update and data acquisition system
• Easily rechargeable integrated battery with fully waterproof, reliable electric system
• Hollow outer chainring, giving vast improvements in rigidity and increased weight savings
• The hollow outer chainring has essentially removed outer chainring flex, hugely improving shift performance, making it precise even under high load
• These industry-leading HollowTech II cold forged hollow crank arms have evolved to increase rigidity, reduce weight, and improve strength
• The teeth have been developed to work only in conjunction with the 12-speed chains for improved contact, providing more efficiency and improved power transfer
• There is a wide range of chainring ratios and crank arm lengths available, enabling customisation for all riders and racing disciplines
• HollowTech II integrated bottom bracket design uses a wider bearing placement and larger axle diameter for increased stiffness and efficiency
• Bottom bracket seal design has a minimal bearing interface, giving superbly smooth rolling and increased durability