This is the Team Orion NiMH 6-cell 3900mAh 7.2V Rocket Stick Battery Pack.

FEATURES: Ideal for backyard bashers and budget racers needing superb
performance at a great price

INCLUDES: One Team Orion 3900mAh 7.2V Stick Battery Pack with Tamiya type
connector

REQUIRES: Timed or peak charger capable of charging NiMH cells

SPECS: Length: 5.4" (137mm)
Width: 1.9" (47.5mm)
Thickness: 0.96" (24.5mm)
Weight: 14.3oz (405g)
Wire Size: 16 AWG