Do I have to turn on/off the device? You do not need. The device turns on and sleeps automatically. Tagged: power meterpowercranktwin2 Related Articles How long does it take to install a power meter? DO I HAVE TO TURN THE METER ON/OFF? WHAT DO THE QUANTITIES RECORDED BY THE METER (TE/PS/LR%) MEAN? HOW DOES THE DEVICE WORK? How to connect multiple devices with each other? – Zwift, Smart Trainer, Bicycle computers etc. Which crank will be compatible with my crankset? – list of replacement cranks