This is a Spektrum RC 2000mAh TX Battery DX6.

Features:

• Built-in charge circuitry
• Charge using a 12-14V power supply
• Compatible with DX6 G2-3, DX7 G2, DX8 G2, DXe, DX6e

Specifications:

• Battery Type: LiIon (3.3V per cell)
• Battery Voltage: 7.4V
• Capacity: 2000mAh
• Connector Type: White TX Plug
• Number of Cells: 2
• Product Height:  0.91" (23mm)
• Product Length: 2.95" (75mm)
• Product Width: 2.28" (58mm)
• Product Weight: 4.48oz (127g)