The ATMega 32U4 runs at 5 V / 16 MHz Supported under Arduino IDE v1.0.1 On-Board micro USB connector for programming 4x10-bit ADC Pins 12 x Digital I/Os (5 PWM capable) Rx and Tx Series Hardware Connections.
There is a voltage regulator on board so it can accept voltage up to 6V(Blue board)/15V(purple board).