This is the Traxxas SERIES 5 5000mAh 9.6V 8C Hump NiMH with iD Technology.

Features:
12AWG multi strand wire
iD Technology
Engineered specifically to fit Traxxas models
Requires:
EZ-Peak Plus 4-amp NiMH/LiPo Fast Charger with iD™ Auto Battery Identification
Depending on model a battery expansion kit might be needed TRA3725X, TRA6727X or TRA5827X

Traxxas Bandit
Traxxas Rustler
Traxxas Slash
Traxxas Slash 4x4
Traxxas Slash 4x4 Ultimate
Traxxas Stampede
Traxxas Stampede 4x4