This device is for Sports & Aviation use only. No Need Replace Batteries: Thisblood oxygen monitor use of charging mode, not need replace batteries. The alarm wakes her up. I only wish the unit base had a longer electric cord, but an extension cord solved the problem.

Brand: HealthTree
MPN: JKS50F
Form Factor: Handheld
Oximeter Type: Pulse Oximeter with Probe
Intended Use/Discipline: Emergency Medicine, Family Medicine, Internal Medicine, Medical Laboratory, Physical Laboratory
Included Probe: Adult Finger Probe
Country/Region of Manufacture: China
Type: Compact Pulse Oximeter
Display Type: OLED
Connectivity: Bluetooth
Colour: White
Features 1: Smartphone Compatible
Features: With Alarm
Power Source: Rechargeable Battery
Unit Type: Unit
Unit Quantity: 1