This is the Racers Edge 25C 5000 mAh 2S1P Li-Poly Battery with Deans Ultra Plug.  This Racers Edge battery is lighter than traditional Ni-Cd or Ni-Mh batteries while offering improved performance and run times.  It uses the standard ballancing connection that comes on most high-performance R/C 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!!!