No backlight required, the last screen display can be for a long time after power failure The power consumption is very low, basically only consuming power when refreshing The following only applies to the module version:Based on for 40PIN GPIO interface design, suitable for , Nano Adopting for the HAT+ standard, the interoperability of the expansion board is improved, helping developers to design and develop faster, use various external devices more easily, and expand the functions and performance of for the Reserved SPI communication interface for easy access to for / for / STM32 / ESP32 and other main control boards Module version: 3.3V/5V Communication interface:3-wire SPI,4-wire SPI Display colors: red, yellow, black, white Grayscale:2 fast refresh:13s Global refresh:21s Refresh power consumption: Less than 90mW point distance:0.108 x 0.108 (mm) Sleep current Less than 0.01uA (close to 0) resolution:800 x 480 pixels Viewing angle: 170 (The product printed words depending on the batch, but this does not affect use) Specifications: A Module board Color: As Shown Material: LCD Package Contents: 1 x 3.97inch e-Paper(The color and style of the screws are random, and specified colors and styles are not accepted) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.