7.4V 2-cell Li-Poly receiver battery packs, with JR type discharge plug. Use a regulator such as the Jeti Max BEC to generate a voltage appropriate for your receiver and servos or use directly with high-power servos such as the Hitec HS-7954SH. These packs are rated at 18C but the maximum current draw is limited by the capacity of discharge wires. Please use these packs only for powering your receiver and servos.