There are some components of your ARES device that will have natural wear based on the frequency of use, or become damaged over time. Here are some brief explanations of these parts and suggested milestones for repair/replacement .
The forehead sensor must be replaced after approximately 60 nights of use or when the sensor
surface becomes pitted or cracked. Use care when cleaning to maximize life of this sensor. See below for examples of worn forehead sensors requiring replacement.