How many hours can I wear it per day?

It is recommended a maximum of 4 hours in a row.

How long can it be worn?

If we refer to the number of hours per day, maximum 4 consecutive hours, because later, due to breathing, it can get wet and it no longer protects well. It can be washed at least 5 times.

How much warranty do I have?

Since it is a hygienic product, the return can only be made if the packaging is not opened.