Different from other finger oximeter, except the SPO2/PR/PI measurements, ODI4 (oxygen desaturation index) measurements is added on M170 pulse oximeter. ODI4 data is helpful for people with sleep apnea. 4 Directions OLED Display Allows you to view the measurement results in any direction. Measure 4 Parameters Quickly and accurately measure SpO2 (blood oxygen saturation levels), PR (pulse rate), PI (perfusion index) and ODI4 (Oxygen desaturation Index of 4%) Data Storing & Data Analysis 8 hours data storing and data analysis function, able to monitor while sleeping constantly. Alarm & Beep Function Beep sound alarm will warm you when your oxygen saturation level and pulse rate are beyond set limits. Automatically Power Off Automatically power off in 8 seconds without finger in, low-power consumption. Suitable for All Ages Suitable for wide range of finger sizes - children to adult, highly recommended to people with sleep apnea. Specifications Display OLED display Parameters SPO2, PR, PI, ODI SpO2 Measurement Range About 70~99% SpO2 Resolution About ±1% SpO2 Accuracy About ±2% Pulse Rate Measurement Range About 30-240bpm Pulse Rate Accuracy About ±2bpm Power 2 x AAA batteries (not included) Product Weight 67g Product Size (L x W x H) 65 x 38 x 35 mm Package Contents 1 x Finger Pulse Oximeter, 1 x Lanyard, 1 x Pouch