Pulse oximetry can be used for at-home monitoring of your oxygen level and pulse for conditions such as chronic obstructive pulmonary disease (COPD), asthma, Congestive Heart Failure (CHF) and others. This features a one button operation which serves as an alarm and pulse sound function. It is designed to shut off automatically when no signal is detected for lower power consumption.   FeaturesThe Finger Pulse Oximeter with LED Screen Display is CE & FDA approved. Ideally suited for use in ahospital, home, community medical treatment, sports healthcare, ect. Can measure Sp02 and Pulse Rate accurately and quickly and features a Sp02 and PR display. Low power consumption with battery voltage low indicator and shuts off automatically when no signal is detected. Pulse sound and Alarm function. .LED Screen with One button operation.   Directions for use:Install 2 AAA batteries into the battery compartment. (not included)Place damp over fingernail as per diagram. Insert one finger fully into the rubber hole of the Oximeter. Press the switch once on the front panel of Oximeter. Both the finger and body should not tremble during use.