Voltage: 4.5-5.5V Current: 40mA Digital Interface: 5V TTL level for UART interface and GPIO Analog Interface: 3.5mm mono-channel microphone connector and microphone pin interface Size: 31mm x 50mm Recognition accuracy: 99% (under ideal environment) Support maximum 80 voice commands, with each voice 1500ms (one or two words speaking) Maximum 7 voice commands effective at same time Arduino library is supplied Easy Control: UART/GPIO