Spektrum RC Transmitter Battery Charge Adapter. This optional charge adapter is great for those wanting to charge their rechargeable Spektrum DX Air Transmitter battery. Package includes one charge lead.  
Features:
Compatible with rechargeable batteries used in the Spektrum DX6 Series, DX7 G2, DX8 G2, DXe, DX6e
Molded gold banana plugs
Length: 4.70 in (120mm)