2S4000DX8PCM : 7.4volt 4000mAh rechargeable Li-PO battery pack for SPEkTRUM RC transmitters such as DX7s, DX8, DX9, and new DX6 & DX7 transmitters that can accomodate the SPMB4000LPTX square LiPO battery. Includes built-in PCM, for smart balance re-charging while installed in the transmitter. Also has built-in safety current circuitry, to prevent overcharging. Replaces original SPEkTRUM battery SPMB4000LPTX. Dimensions: Length: 2.7"(68mm), Width: 2" (52mm), Height: 0.75" (19mm).
Important note: SPEkTRUM has enhanced their transmitter product line, and has several new & improved radios with pre-existing model numbers. Certain new issue DX6 and DX7 radios now accept this 7.4v 4000mAh LiPO battery. To verify if your radio is compatible with out 2S4000DX8, open the battery compartment on the back of the transmitter, and see if the cavity will accept the battery per the dimensions listed above.