This is the 7.2V NiMH 1200mAh Power Series 1 Battery Pack from Traxxas.

Features:
Stick configuration.
Used in the 1/16 scale Traxxas Slash and E-Revo VXL.
MAXX cable high-efficiency 16 gauge silicone jacketed wire.
New high current connector with gold-plated copper terminals and iD Auto Battery Identification allows Traxxas iD equipped chargers to automatically set and optimize charge settings for specific battery.

Includes:

(1) NiMH Battery Pack

Requires:
Peak-detecting charger rated for NiMH batteries

Specs:
Length: 94mm (3.7")
Width: 34mm (1.3")
Height: 17mm (0.67")
Weight: 5.1oz (145g)

This product is compatible with the following Model(s): 1/16 E-Revo Brushed Motor RTR 27MHz (7105), 1/16 E-Revo VXL 4WD TQ 2.4GHz RTR (71074), 1/16 Grave Digger RTR (72024), 1/16 Slash Brushed RTR 2.4GHz (70054), 1/16 Summit VXL 4WD (72074)