This is the 1S 3.7V 150mAh LiPo Battery for the MD530 and Axe 100 FP helicopters from Heli-Max. FEATURES: Made especially for the MD530 and Axe 100 FP helicopters Replaces worn or damaged LiPo batteries INCLUDES: 1S 3.7V 150mAh LiPo Battery REQUIRES: Charging with the USB 1S charger (HMXP2021), if using other charger, see COMMENTS below SPECS: Length: 1.8" (46mm) Width: 0.45" (11.5mm) Thickness: 0.24" (6mm) COMMENTS: The charge lead with Banana Plugs and HeliMax Micro Plug (GPMM3150) can be used with this battery by plugging the banana plugs into the opposite jacks in the charger-red to black and black to red. jxs 11/14/12 ir/jxs