Pro Mini ATmega328P ( Arduino Compatible ) Micro-controller Module. 
The USB-TTL 6 pin with DTR module is ideal for programming this board.
Specifications
 
Microcontroller
ATmega328P
Operating Voltage:
+5vdc ( +3.8-12vdc Recommended )
Digital I/O Pins:
14 of which 8 are analogue and 6 provide PWM
DC Current I/O:
Maximum 150mA
Flash Memory:
32 KB ( ATmega328 ) of which 2KB is used by the bootloader 
SRAM:
2KB
EEPROM:
1KB
Clock Speed:
16MHz
Board Size:
33mm L x 18mm W x 6mm H