The PowerTap GS 24 Hole Straight Pull Hub WDT Swiss Internals is more robust than ever, thanks to its completely redesigned DT Swiss hub body, with DT Swiss 240 straight pull shells and DT Swiss bearings for ultra reliable, smooth rolling performance. It delivers 1. 5% accuracy for precise power measurement when you're training for an upcoming race and maximizing endurance. Using the same power meter design as the G3, the GS has its electronics built into a removable end cap. This allows you to swap out end caps, should you experience a reading problem, instead of sending the entire wheel into PowerTap for analysis. Furthermore, the removable end cap facilitates easy battery replacement, using a single CR2032 battery that's good for some 300 hours of riding time. More than simply a power meter, the GS Hub measures speed and cadence with high levels of accuracy. It wirelessly communicates with ANT cycling computers for real time analysis when you're riding. Moreover, you can fit the GS Hub with a Bluetooth Smart PowerCap sold separately that's compatible with popular cycling apps, such as PowerTap mobile, Strava, and MapMyRide.