These displays are small, only about 1" diagonal, but very readable due to the high contrast of an OLED display. This display is made up of 128x32 individual white OLED pixels, each turned on or off by the controller chip .As the screen makes its own light, no backlight is required.This reduces the power needed to run the oled and that's why the screen has such high contrast;We really like this miniature screen for its sharpness The SSD1306 driver chip, only communicates via SPI, 4 or 5 pins are needed to communicate with the chip in the OLED display. The oled and the driver require 3.3V power supply and 3.3V logic levels for communication.To make it easier for our customers to use, we have added a 3.3v regulator and level lever on board This makes it compatible with any 5V microcontroller , such as the arduino. The power needed depends a bit on the brightness of the display, but on average the display uses about 20ma from the 3.3V supply. Built into the OLED driver is a simple switch cap charge pump that turns 3.3v-5v into a high voltage drive for oldies, making it one of the easiest ways to get an OLED into your project Dimensions: PCB: 23mm x 32mm x 5mm / 0.9" x 1.26" x 0.2" Mounting Hole Distance: 17.08mm x 25.8mm / 0.67" x 1.0"Mounting Hole Diameter: 3mm / 0.11" Display Area: 7mm x 25mm Show Details: Diagonal Screen Size: 0.91" Number of Pixels : 128x32 Color depth: Monochrome (white) Building module: COG Module size (mm): 46.30x11.50x1.45 Panel size (mm): 30.00x11. 50x1.45 Active Area (mm): 22.384x5.584 Pixel Pitch (mm): 0.175x0.175 Pixel Size (mm): 0.159x0.159 Interface: SPI 4-wire