With an industry leading accuracy of 1. 5%, Quarq's BB30 Riken R Power Meter Crank Arms guarantees to transform your training and give you an edge over the competition. Quarq's OmniCal power measurement technology allows you to switch chainrings without needing to recalibrate, making the swap between your road, 'cross, and tri setups quick and easy. The Riken R uses the 10k dynamic temperature compensation feature to prevent re zeroing in extreme temperatures, so all you have to worry about is turning the cranks. The CR2032 gives you up to 300 hours of ride time, and when do you have to replace it, you can do it yourself, without any tools this is far better than having to mail it back to the manufacturer, which is what most systems require. To boot, Quarq designed the Riken R to be waterproof for 30 minutes while submerged under one meter of water. To communicate data to your head unit, the Riken R uses ANT wireless so your current computer is most likely already compatible with it. The Riken R uses an AxCad accelerometer to measure cadence, and it's compatible with various training software such as Training Peaks WKO, Golden Cheetah, and Strava. This model is compatible with BB30 bottom brackets and SRAM 10 and 11 speed and Shimano 10 speed drivetrains. For 11 speed Shimano compatibility, check out the Elsa RS model.