This is the Traxxas 1400mAh 11.1V 3C 25C LiPo with Auto Battery iD TRA2823X.

Features:
Engineered specifically to fit Traxxas models
Semi rigid construction does not require a hard case and eliminates wire harness connectors that can loosen and fail
16AWG multi strand wire is soldered directly to the LiPo cells eliminating increased resistance from bullet connectors and accidental reversed polarity connections
Includes:
One Traxxas Power Cell 11.1V 1400mAh 25C LiPo 3S Battery with High Current Connector and JST/XH Balance Plug

Traxxas 1/16 E-Revo
Traxxas 1/16 Mustang
Traxxas 1/16 Race Truck
Traxxas 1/16 Rally
Traxxas 1/16 Slash
Traxxas 1/16 Summit
Traxxas TRX-4
Traxxas TRX-4

Requires:
Balancer and LiPo compatible charger or LiPo charger with built-in balancer such as the Onyx 235, DTXP4235 LiPo charging bag
Specs:
Configuration: 3S2P
Continuous Discharge: 25C (35A)
Max Burst Rate: 50C (70A)
Watt Hours: 15.54
Charge Rate: 1C (1.4A)
Max Charge Rate: 2C (2.8A)
Dimensions: 3.5 x 0.8 x 1.8" (88 x 20 x 35mm)
Weight: 3.7oz (104g)