Specifications: Display mode: LCD display SpO2 display: 35%~99% Pulse rate display: 30bpm-240bpm Pulse wave''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s intensity display: 15-segment bar-graph display Low battery voltage indication: segment LCD signal Power supply requirement: 3. 7V lithium battery (680Ah) Operating current: <40mA Resolution: SpO2+/-1% Pulse rate: +/-1bpm Accuracy: SpO2 +/-2% (during 70%-99%) No definition (<70%) Pulse rate: +/-2bpm Measurement at low perfusion: The values of SpO2 and pulse rate can be displayed properly when pulse saturation is at 0. 5% Resistance to surrounding light: The difference between the value measured in the condition of indoor natural light and that of darkroom is less than +/-1% Resistance to interference of man-made light: The difference between the value measured in the condition of man-made light and that of darkroom is less than +/-1% Automatic shutdown function: The device will power off automatically in 8 seconds when there is no finger in the device Dimensions (L x W x H): 65 x 35 x 40mm Weight: 60g [including 1. 5V (AAA size) alkaline batteries x 2] Environment requirements: Temperature: Operating temperature: 10C ~ C Storage temperature: -20C~ 55C Humidity: Operating humidity: 35%~80% Storage humidity: 10%~100% Atmospheric pressure: Operating pressure: 70kPa~106kPa Storage pressure: 50kPa~106kPa