The size of the oximeter is 5. 7*3. 2*3. 3cm. Accurately determine your SpO2 (blood oxygen saturation levels), pulse rate and pulse strength in 10 seconds and display it conveniently on a large digital LED display. For sports enthusiasts like mountain climbers, skiers, bikers or anyone interested in measuring their SpO2 and pulse rate. SpO2 and Pulse Rate now faces instead of away from the user for easy read.