This is a Traxxas 4S 14.8V 5000mAh 25C Long LiPo Battery Pack. Traxxas Certified iD-Equipped LiPo batteries are engineered to provide the punch and on-demand power for reaching the top speeds that Traxxas models are built to achieve. Traxxas Power Cell iD-Equipped LiPo batteries are engineered specifically to fit Traxxas models and maximize their full performance potential. Only Traxxas gives you more of what you want most: simple installation, a great price, and the most speed and run time available.