How do you define success? Whether you are fighting for a Kona slot, spending countless hours on the indoor trainer or striving for a personal best; one thing we know, success takes time.With up to 800 hours of battery life, +/-1% accuracy and backed by our legendary 3-year warranty, the PRECISION 3 Powermeter will be your trusted training tool for years to come.A Ride Ready PRECISION includes and comes preinstalled on a brand-new Shimano crank arm of your choice. These crank arms will fit bottom brackets using the Hollowtech II interface.-3D Power Measurement - 4iiii's patented 3D power measurement system measures multidimensional strain, so you can be confident that your unique pedal stroke is still measured accurately no matter your riding conditions.-Ultra Low Profile - Now compatible with more bike frames than ever before-Indicator Light - At a glance, you can now see when your power meter has turned on, performed a successful Zero-offset, or has a low battery.-Waterproof - With an IPX7 waterproof rating you can be assured that your power meter can handle the toughest conditions.-ANT+ & Bluetooth - The PRECISION 3 Powermeter is both ANT+ and BLE compatible so you can use it on your preferred head unit and favorite indoor training app.