4-Pack of E-flite 3.7 volt 150mAh 25C Lipos for Blade mCX mCX2 mSR mSR X Nano QX Nano CPX UMX AS3Xtra Stock up on these batteries for more flight time! Popular battery in many rc applications 4 Pack of 150mah 25C batteries included (total of 4 batteries) Weight 4.15g (0.14oz) for each battery