This has many Features including Tiny, light, "all-in-one" integrated clip design,easy for carrying; LED screen with SpO2, PR and Pulse strength measurements; Immediately, real-time spot-check; Single button interface, easy for operation, Common AAA alkaline or rechargeable batteries to support 3 continuous working hours; Low battery power indicator; and Automaticpower-off. Standard accessories include one Fingertip pulse oximeter main unit, one Lanyard.