Ems500a Finger Tip Oximeter for Sports and Recreation with Adjustable alarm function light weight, portable , Color OLED display, 4 direction run on 2 x aaa battery for 30 hours continuous use. auto shut off in 8 sec. when idle Adjustable audio alarm range:the safety range of SPO2 and pulse rate are adjustable For sports and recreation use . not a medical device comes with oximeter , battery and neck strap