LED viewing screen with PR,SPO2, Bar Graph LED viewing screen with PR,SPO2, Bar Graph "All-in-one" integrated finger deviceSimple operation for immediately, real-time spot-checks.Reliable accuracy and durability.30 hours continuous use.Low voltage indicator.AAA Alkaline & rechargeable battery is availableAutomatic power-off design. Standard Accessory2 AAA Alkaline batteriesOperating manualHang ...