There are 54 Digital IO pins and 16 analog sticks built into the handlebars that make the device unique and protrude from others. It comes in 4-inch length and 2.1 inches width. However the USB port and the power outlet are slightly lengthened from the given dimensions. Note that these pins are not in the same place as TWI Pins on the old Duemilanove or Diecimila Arduino boards. Note: Although valid values and defaults in the preceding table are written with the prefix 0x to indicate that they are hexadecimal numbers the module does not include 0x when reporting the value of a parameter and you should omit it when entering values. Second it has built-in RTC and other features like analog comparator advanced timer scratch for leading wake mechanism to save more power and fast speed with 16 MHz crystal clock to get 16 MIB.There are 54 digital IO pins and 16 analog pins incorporated on the board that make this device unique and stand out from others.It comes 4-inch length and 2.1-inch width. However USB port and power jack are slightly extended from the given dimensions.Note that these pins are not in the same location as the TWI pins on the old Duemilanove or Diecimila Arduino boards.Note: although the valid and default values in the table above are written with a prefix of 0x to indicate that they are hexadecimal numbers the module will not include the 0x when reporting the value of a parameter and you should omit it when setting values.Secondly it has inbuilt RTC and other features like analog comparator advanced timer interrupt for controller wakeup mechanism to save more power and fast speed with 16 Mhz crystal clock to get 16 MIBS.