CAT No. PO-300D Display Format LCDSPO2 35-99%Pulse Ratio:30-255 BPMPulse 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 Ratio.