Product parameters: Display screen: 7.5-inch three color (black, white, red) electronic ink screen x 2 Resolution: 800 * 480 (Dpi 125) Appearance material: ABS+aluminum alloy Material Appearance dimensions mm (length * width * height): 208mm x 44mm x 150mm Product features: low power consumption, 3-5 years of battery life for regular use; Support air wake-up, refresh quickly, and see results within seconds; Dot matrix electronic paper screen, with a viewing angle close to 180 °, displaying a natural and realistic paper effect; Web based application interface, supporting cross platform operations; Easy installation and quick layout; Battery powered does not require wiring; Double sided display (supporting dual sided display), beautiful, simple and elegant; Can be used directly without installation during use; Easy to operate interface, no need for learning, quick to get started, wireless communication distance of 30m; wireless communication speed of 50/250kbps; Customize bidirectional communication protocol; Data software and hardware verification; Working temperature: 0-50 degrees, strong penetration, not afraid of obstacles