Two Color OLED Display, Six display modes. 4-Direction Display automatically. Visual alarm function. Real-time spot-checks. Low Power consumption. 50 hours continuous to work. Low Perfusion ≤0.4%. Low voltage indicator. Automatic power off when no signal. Reliable accuracy and durability. Small and light weight, convenient to carry. Vacuum-galvanization technique and UV printing technology employed to create this wonderful product with specular appearance, it is fashion and durable.