This is the Traxxas Power Cell 11.1V 5000mAh 25C 3S LiPo Battery.

Features:
Semi rigid construction does not require a hard case and eliminates wire harness connectors that can loosen and fail.
Engineered specifically to fit Traxxas models.
New high current connector with gold-plated copper terminals and integrated balance connector.
iD Auto Battery Identification allows Traxxas iD equipped chargers to automatically set and optimize charge settings for specific battery.
MAXX cable high-efficiency 12 gauge silicone jacketed wire.

Includes:

(1) Battery with High Current Connector and Integrated Balance Plug

Requires:
LiPo compatible charger such as the Traxxas EZ-Peak Plus
LiPo charging bag

Specs:
Configuration: 3S1P
Continuous Discharge: 25C (125A)
Max Burst Rate: 50C (250A)
Watt Hours: 55.5
Charge Rate: 1C (5A)
Max Charge Rate: 2C (10A)
Dimensions: 6.1 x 1.02 x 1.7" (155 x 26 x 44mm)
Weight: 13.3oz (376g)

This product is compatible with the following Model(s): Traxxas Hoss,Traxxas Stampede 2WD,Traxxas TRX-4,Traxxas M41 Catamaran,Traxxas TRX-6,Traxxas XO-1,Traxxas XRT,Traxxas Bandit,Traxxas 4-Tec 2.0,Traxxas Slash 4X4,Traxxas Unlimited Desert Racer,Traxxas E-Revo,Traxxas Rustler 4X4,Traxxas Maxx,Traxxas Sledge,Traxxas Slash 2WD,Traxxas Drag Slash,Traxxas Rustler 2WD,Traxxas X-Maxx