Display mode: LED SPO2: Measurement range: 35-99% Accuracy: +-2% Pulse: Measure range: 30-240 BPM Accuracy: +-2 BPM Pulse Intensity: Bar graph Indication Power Requirements: Two AAA alkaline Batteries Battery consumption: Two AAA 1.5V, 600mAh alkaline batteries can be continuously used as long as 30 hours Dimension: Length: 58mm (2.28") Width: 32mm (1.26") Height: 34mm (1.34") Weight: 50g (1.77 ounces) - including two AAA batteries