Technical Parameter: Display Format: LCD SPO2:35-99% Pulse Ratio:30-255 BPM Pulse Wave: LCD Numeric Display Battery Voltage Low Indication: LCD Bar Graph. Power Requirements: Two AAA size 1.5V Alkaline Batteries Power Consumption: less than 15 mA. Resolution: 1% for SPO2 and 1 BPM for Pulse Rate. Measurement Accuracy: í+2% in stage of 70%-99% for SPO2 Unspecified in stage of 35-69% for SPO2 í+2BPM or í+2%(Select Larger)for Pulse Rate. Measurement Performance in Low Perfusion: SPO2 and pulse & rate can be shown correctly when pulse-perfusion ratio is 0.4% Interference Resistance Capacity against Ambient Light : Deviation is smaller than í+1% It is equipped with a function switch, through which the Oximeter can be automatically powered off when no finger is in the Oximeter more than 4 seconds