Power meter is a device that measures the power generated by the cyclist during his race and is an essential element of a cycling training. The device is installed on the left arm of the Shimano crank mechanism. ANT+ and Bluetooth Low Energy allow you to connect to a wide range of bike computers. In addition, the INPEAK power meter will connect to a smartphone and you will take advantage of many applications to analyze and record data. The use of inertial IMU sensors and filtering algorithms that minimize the negative impact of vibration from ground irregularities (off-road driving, potholes in the asphalt or cobblestones). Precise and accurate readings of the generated power regardless of weather conditions provides an ATC automatic temperature compensation mechanism in the range of -5°C to + 50 ° C. Regardless of the conditions, you can rely on the watts. Weather-independent operation is guaranteed by the IP67 housing tightness class. Don´t worry about dirt, rain or dust. Just enjoy. Due to the low power consumption, it is not necessary to change the batteries frequently. Due to the low power consumption, it is not necessary to change the batteries frequently. Replace the left arm of your bike crank with the product you purchased TECHNICAL SPECIFICATIONS:Communication: ANT+, Bluetooth Low EnergyPower supply: 1X CR2032 batteryBattery life: MAX. 200 hoursMeasurement accuracy: ±2%Weight: left hand serial weight + 12GHousing tightness: IP67Measuring range: 0-2000 [watts] Cadence range: 20-200 [rev./min] Operating temperature: -5°C to + 50°C