WRINERY Innovated and Premium Quality Pulse OximeterPortable and compact size -- The oximeter weighs only 0.5 ounces with a lanyard for easy carrying. Convenient for home and travel. Easy battery loading -- The oximeter is driven by 2 x 1.5V (AAA size) batteries for up to 15 hours of continuous operation. If the battery icon remains on the OLED display, then it is an indication of low battery level. Large and clearer display -- Our oximeter chooses and OLED display, which is quite clearer than other oximeters equipped with LED screens, it enables accurately value readings in any environment. Get to know your SpO2 and Pulse Rate anytime and anywherePulse Oximeter is not intended for medical use, this device is suitable for use at home or travel, it can accurately and reliably determine your SpO2 (blood oxygen saturation levels), Pulse Rate and Pulse Strength before and after any strenuous activities. Designed for sports enthusiasts, aviators, trainers, bikers, mountain climbers or anyone who wants to obtain their SpO2 on the go. Quick and easy operation in three simple stepsRemove the back cover and install the two AAA batteries. Insert your finger by aligning it with the red light and wait for the oximeter to switch on. Read the results after eight to ten seconds. Portable and Easy to Carry 1 x Finger Oxygen and Heart Rate Monitor1 x Lanyard 1 x User Manual 2 x AAA Batteries1 x Carrying case