NOTE : The manufacturer has updated the battery installation method. Refer battery slot direction which is already indicated while battery installation. Determine your SPO2 and Pulse Rate in 10 seconds or less displayed on its large digital red LED display. SPORT/HEALTH ENTHUSIASTS - For sports enthusiasts like mountain climbers, skiers, bikers or any sports enthusiasts interested in measuring their SPO2 and pulse rate. Included: 2 AAA Batteries, FREE Carrying Case, Lanyard, User manual, Machine and our Full One-Year Warranty NOTE: This device is for Sports & Aviation use only and is not a medical device.