Whether chasing KOMs up steep climbs or riding virtually on Zwift in our living room, the Shimano GRX RX810 PRECISION 3+ Left-Side Power Meter measures and transmits our watts, cadence, and calories directly to our head unit with a +/-1% accuracy rate. It features an excellent battery life of up to 800 hours, an ultra-low and lightweight profile, and ANT+ and Bluetooth connectivity for use with our favorite apps and units. This left-side power meter comes ready to use straight out of the box, needing only to be installed on our Shimano GRX FC-RX810 crankset with the standard Shimano crank installation process.