Arduino UNO uses ATMEGA328P-PU microcontroller and this controller comes pre-loaded with a Arduino UNO bootloader. Basically bootloader is a little piece of code that allows you to program the flash memory of the Arduino’s atmega328p via serial or USB instead of using an ICSP programmer.
7-12V DC;OutputVoltage : 5V/3.3V 1 x Prototype Shield Expansion Board,1 x Bread Board Materials : Plastic, PCB; Net Weight : 44g Ideal accessories is suitable for arduino mega. Great for DIY project. Prototype Shield Board Kits;Fitfor : for Arduino Mega