Accurately calibrated strain gauges are integrated inside both left and right crank arms, providing a stable measurement system through rotation from both sides for extremely precise data. With +/-2% accuracy of strain gauge measured power, this chainset is suitable for professional teams and serious cyclists. It also features Bluetooth and ANT+ connectivity with wireless firmware update and data acquisition system. The easily rechargeable integrated battery has a fully waterproof and reliable electric system. The hollow outer chainring provides vast improvements in rigidity and increased weight savings, removing outer chainring flex and improving shift performance even under high load. The industry-leading HollowTech II cold forged hollow crank arms have evolved to increase rigidity, reduce weight, and improve strength. The chainset is available in a 52-36t size and is suitable for unisex cyclists.