1. Advanced DSP algorithm can minish the influence of motion artifact and improve measurement accuracy of low perfusion. 2. Pop-up Menu to setup alarm limits 3. Small size, lightweight and convenient in carrying. 4. Lower power consumption and the two AAA batteries can be operated continuously for 20 hours. 5. Battery low voltage indicator in visual window. 6. The product will automatically be powered off when no finger is in the device for longer than 8 seconds. Specifications Displays: Color 1.0 inch OLED Plethysmogram, Oxygen Saturation, Pulse Rate, Bargraph Battery Indicator Pop-up Menu Four display directions. Oxygen Saturation Range (%SpO2) 0% to 100% Pulse Rate Range (bpm) 30 to 250 pulses per minute Power Options Two AAA batteries 20 hours typical operation Probe Red light LED wavelength 660nm Infrared light LED wavelength 940nm Dimensions 58mm L *36mm W* 30mm H Weight 50g with two batteries