Feature: - Two color OLED display more display modes - Low-power consumption continuously four directions adjustable - Low voltage indicator - Automatically power off in 8 seconds when there is no signal - Small in volume lightweight for convenient to carry - Can be used in hospital home community medical treatment sports healthcare etc. Others feature:SpO2: Measurement range: 70~99%; Resolution: 1%; Accuracy: 70%~99% +/- 2% unspecified <70% - Pulse rate: Measurement range: 30~240bpm Resolution: 1bpm Accuracy: +/- 2bpm or +/- 2% (select larger) - Power: 2 x AAA alkaline batteries (not included) - Power consumption: <=30mA - Working voltage: DC 3V working time over 40 hours