Link to the selling company: "PPE and Medical Diagnostic Equipment Manufacturers - Obetech Medical" https://www.obetechmedical.com/about/
A very good price for that device.
Seems to be a reputable medical supplies distributor.
Oxygen Saturation Monitor, Smart Functioning SPO2 Pulse Oximeter with Plethysmograph, Lanyard, Batteries, and User Guide.
This or the Apple Watch series 6?