The Stages Power L meter paired with FSA's SL-K Light BB30 left crank arm. Please note that the SL-K Light BB30 version has across the board compatibility with FSA and Vision BB30 models.The new Stages Power meter is slimmer, and up to 28-percent lower profile than our original meter. It's sleeker by way of a 17-percent reduction in frontal area, and we've also made it stronger. The new housing design increases the strength of the battery door and housing connection by 200-percent over the previous design.SPECIFICATIONS:Stages Power L Accuracy: ± 1.5% (Compared with Generation 2 Accuracy: ± 2%),Power Meter Housing: new low profile design, with new door interface,Weight: Only adds 20g to base crank arm,Battery Life: 200+ hours (coin cell: CR2032),Power range (Watts): 0 - 2500,Cadence range (rpm): 20 - 220,Water resistance rating: IPX7,Frame Compatibility: Most frames, see fit guide in our Support section,Device Compatibility: ANT+, Bluetooth Smart Ready,Software Compatibiity: Training Peaks, Strava, Garmin Training Center and others.ADDITIONAL FEATURES:Tool free battery replacement,Active temperature compensation,Accelerometer based cadence measurement,Wireless firmware upgrades.