Racers Edge 30C 5200mAh 11.1volt 3S1P LI-Poly Battery with TRX plug.This hardcase 3s lipo battery offers superior voltage and long runtimes.  The dimensions are 47mm wide, 138mm long, and 38.5mm tall, making it the perfect fit in any Traxxas Stampede, Rustler, or Bandit using the battery expansion kit, part # TRA3725x. This battery is also a great option for 1/8th scale electric buggies, with plenty of voltage and a great 30C power rating. It uses the same balancing connection as Align or Electrifly chargers. Be sure to use a voltage cut off if your speed control doesn't come equipped with one. ONLY USE A CHARGER SPECIFICALLY FOR Li-Poly cells!!!