Sleep SpO2 Ring Sensor, O2 Ring Probe for CheckmeO2 Max, Visual Oxy, Oxiband, SleepU Note: This is only an accessory and does not include native device. Sensor for CheckmeO2 Max Sensor for SleepU Sleep Ring for Visualoxy Probe for Wearpulse Sleep Monitor The texture is soft, and the material uses silicone. USB socket.