With the Extended Transmit option an internal power supply with nearly 50 Watts capacity is used. A large energy storage capacitor provided within the system allows transmit for bursts with much higher energy levels, provided that enough time is allowed between bursts to recharge the capacitor from the internal supply. Approximately 20 Joules of energy is available from this capacitor (e.g. enough to provide 200 Watts output level for 0.1 second, or 2000 Watts for 10 milliseconds). The Extended Burst option is available on the Vantage 256, Vantage 128 and Vantage 64LE systems.