What is an UNO R3 (Arduino Compatible) Board?

UNO R3 Development Board ATMEGA328P Chip CH340G with cable (Compatible with Arduino UNO)

Uno R3 Rev3 Development Compatible Board

UNO R3 Board with ATMega328P+ATmega16u2(Arduino-Compatible)

SainSmart UNO R3 ATmega328P Development Board + 2 Channels Relay + Free USB Cable Compatible with Arduino –

Compatible with Arduino UNO R3

EDArduino UNO-C Arduino-Compatible R3 Board, CH340 - ElectroDragon

Camkey UNO Project Super Starter Kit with Tutorial and UNO R3 Compatible with Arduino IDE

SainSmart UNO R3 ATmega328P Development Board + 2 Channels Relay + Free USB Cable Compatible with Arduino –

Arduino UNO Compatible Board ATmega328