This is an E-Ink display module, 2.9inch, 296x128 resolution, with embedded controller, communicating via SPI interface, supports partial refresh. 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. 

• 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.
• Comes with development resources and manual (examples for Raspberry Pi/Arduino/STM32)

• Operating voltage: 3.3V
• Interface: 3-wire SPI, 4-wire SPI
• Outline dimension: 89.5mm × 38mm
• Display size: 66.89mm × 29.05mm
• Dot pitch: 0.138 × 0.138
• Resolution: 296 × 128
• Display color: black, white
• Grey level: 2
• Partial refresh time: 0.3s
• Full refresh time: 2s
• Refresh power: 26.4mW(typ.)
• Standby power: <0.017mW
• Viewing angle: >170°

• Wiki