These displays are small, only about 1" diameter, but very readable due to the high contrast of an OLED display. This display is made of 128x64 individual OLED pixels, each one is turned on or off by the controller chip. Because the display makes its own light, no backlight is required. This reduces the power required to run the OLED and is why the display has such high contrast; we really like this miniature display for its crispness!
This breakout can be used with either an SPI or I2C interface - selectable by soldering on the back. It comes with SPI as the default interface. The design is completely 5V-ready, with an onboard regulator and built in boost converter. It's easier than ever to connect directly to your 3V or 5V microcontroller without needing any kind of level shifter!
This is a very popular display with numerous tutorials, sample codes and libraries available to use it. Libraries are available with functions for printing print text, bitmap images, pixels, rectangles, circles and lines.