A4: Measures SpO2 and HR; 2 color 4 model OLED display; Automatic 4 direction display; Battery works for 50 hours; Perfusion <0.4%; Automatically power off. A2: Measures SpO2 and HR; LCD display; Battery works for 50 hours; Perfusion <0.4%; Automatically power off. More Product Features Trademark: Zondan Model NO.: A2, A3, A4, A5 Standard: CE Company: Shenzhen Hexin Zondan Medical Equipment Co., Ltd
