Overview
This is an E-Ink display module, 4.2inch, 400x300 resolution, with embedded controller, communicating via SPI interface, supports red, black, and white three-color display.
Due to the advantages like ultra low power consumption, wide viewing angle, clear display without electricity, it is an ideal choice for applications such as shelf label, industrial instrument, and so on.

Features
No backlight, keeps displaying last content for a long time even when power down
Ultra low power consumption, basically power is only required for refreshing
SPI interface, for connecting with controller boards like Raspberry Pi/Arduino/Nucleo, etc.
Onboard voltage translator, compatible with 3.3V/5V MCUs
Comes with development resources and manual (examples for Raspberry Pi/Jetson Nano/Arduino/STM32)
Specifications
Operating voltage: 3.3V~5V
Interface: 3-wire SPI, 4-wire SPI
Outline dimension: 103.0mm × 78.5mm
Display size: 84.8mm × 63.6mm
Dot pitch: 0.212 × 0.212
Resolution: 400 × 300
Display color: red, black, white
Grey level: 2
Full refresh time: 15s
Refresh power: 26.4mW(typ.)
Standby power:
Viewing angle: >170°

Package Content
4.2inch e-Paper Module (B) x1
PH2.0 20cm 8Pin x1

Development Resources
Wiki : www.waveshare.com/wiki/4.2inch_e-Paper_Module_(B)