ITEM NAME:1PCS Arduino Pro Mini Board Free with Headers ATMEGA328P 16MHz 5V Descriptio n Material: electronic components, etc. Size: 33.3*18mm Packing: 1PCS ATMEGA328P Arduino Pro Mini Board - 14 Digital input and output ports (TX, RS ....) - TTL level serial tranceiver port RX/TX - 6 PWM ports, D3, D5, D6, D9, D10, D11 - Uses Atmel Atmega 168p microcontroller - Supports serial download - Support for external 5v-12v DC power supply - Support 9V Battery.Support 9V Battery Powered operation. - TTL level serial tranceiver port RX/TX. We'd like to settle any problem in a friendly manner. We want to make sure you are happy with our item. Goods without RMA number will NOT be accepted.