Deans Type connecter leads for connecting 2 lipo batteries in SERIES. Connecting lipo batteries in series will keep the capacity the same but double the voltage output. For example, when connecting 2 X 1300mAh 11.1v lipo battery packs in series you will get a 1300mAh 22.2v lipo battery pack. Connecting the batteries in parrallel will doublethe capacity and keep the voltage the same. Comes with instructions on how to series 2 lithium polymer batteries together