With the Red AXS Power Meter Spider from SRAM, you can easily upgrade your SRAM AXS crankset into a power meter. By simply unbolting the eight T20 Torx bolts that hold your current spider to the drive side crankarm and installing this unit, you'll start to receive important ride metrics like cadence and wattage. Its 107mm bolt circle diameter works with both 1x and 2x setups offering the maximum in versatility down the road. Like the rest of its 12-speed electronic road and mountain groups, the Power Meter Spider is AXS enabled, SRAM's newest electronic integration platform that connects the components to an easy to use app. It allows you to monitor battery status and perform firmware upgrades. Information is sent to your smartphone, tablet, or head unit via Bluetooth Low Energy or ANT+ connection and the power readings are accurate to within +/-1. 5% and aren't affected by changing climate conditions during your ride. Lastly, the spider measures the power balance between your left and right legs separately, letting you maximize training and dialing in your position.