wellue Bluetooth oximeter fingertip supports real-time monitoring. 111 Technical Specifications: Display Type : OLED Shown on screen: O2 level, PR, Pulse Bar, Battery, Heart Rate Wave, Analysis Result of PR on Mode "Spot check", Record List of History, Setting Menu O2 level Measurement O2 level display range: 35%~100% O2 level measuring accuracy: ≤ 2% for O2 level range from 70% to 100% Pulse Rate measurement PR display range: 30bpm~240bpm PR measuring accuracy: ±2bpm or ±2% (whichever is greater) Perfusion Index(PI) Display range 0%~20% Over-limit settings O2 level low limit setting range: 85%~99%, step: 1% Default setting: 90% Pulse Rate Low limit setting range: 30~60bpm, step: 5bpm; High limit setting range: 100~240bpm, step: 5bpm; Default setting: high: 120bpm; low: 50bpm Power supply requirement 2 x LR03 (AAA) alkaline batteries Supply voltage: 3.0VDC Operating current: ≤40mA Environmental Conditions Operating Temperature:5°C ~40°C Operating Humidity: 30%~80% Atmospheric pressure: 70kPa~106kPa