Designed specifically for Magic Flight Launch Box, this set of 2 rechargeable NiMH batteries offers rapid heating, long battery life, and convenience. Simply press the battery into the port to activate the MFLB heating system. You can keep an extra battery on-hand for continuous use. NiMH batteries are constructed from high-grade nickel and used principally for high-drain devices, offering more power than alkaline batteries. Each set of MFLB batteries comes with rubber caps to protect the positive terminals.