The Baseline 12-1927 Deluxe Fingertip Pulse Oximeter with Waveform is a convenient, reliable method of measuring blood-oxygen saturation SpO2 and pulse rate. The Baseline 12-1927 is a compact, lightweight unit with a large, easy to read digital display for easy use on the go. The digital display offers SpO2 percentage, heart rate in beats per minute and a real-time plethsmograph waveform to indicate functionality of the heart. Display brightness is adjustable and screen direction may be oriented in 6 different directions. A plethsmograph is established by measuring the change in volume of arterial blood at the fingertip as it fluctuates with one's pulse rate. Waveform, SpO2 and pulse rate are offered in real time readouts simultaneously. Each Baseline 12-1927 Pulse Oximeter includes 2 AAA batteries with a low battery indicator as well as a convenient lanyard Manufacturer # 12-1927 Manufacturer Fabrication Enterprises 1 Each / Each