This is the Traxxas Completer Pack that includes the 200W EZ-Peak Dual Battery Charger with iD Auto Battery Identification, and (2) Power Cell 14.8V 6700mAh 25C 4S LiPo Batteries.The Battery/Charger Completer Pack (#2997) is the perfect complement to your 8s equipped X-Maxx. The pack includes two 4-cell 6700mAh iD LiPo battery packs for 50 mph tire-scorching 30 volt power. Traxxas iD batteries are the easiest and safest LiPo charging solution when used with our exclusive iD chargers. You just plug in your iD battery and press start. The iD charger handles all the settings and quickly gives you an optimized charge every time. The new 4s capable EZ-Peak Live Dual multi chemistry charger comes equipped with built-in Bluetooth to work with the new EZ-Peak Live™ app for iOS and Android. The app gives you detailed information and advanced operation through a high-definition color interface. EZ-Peak Live Dual is the most powerful, versatile, and technologically advanced charger in the popular EZ-Peak iD lineup.