The product information states that this collar is meant to limit excessive movement and to be used in situations such as after neck strain, during recovery, or during prolonged sitting and travel. It does not give a specific number of hours per day, which is important: how long you wear it depends on why you are using it and on professional advice. A doctor or physiotherapist can set a schedule based on your situation and gradually reduce the wearing time as the neck becomes more stable.
In practice, collars of this type are usually worn for defined periods rather than all day long. For example, a person might wear it during activities that involve a lot of head movement, such as working at a desk or travelling, and take it off at home when sitting still or lying down. This approach makes it easier to keep the neck muscles active and avoid stiffness. Continuous, round-the-clock wear is not something you should decide on your own, even if you feel better with the collar on.
If you only started using the collar recently, begin with short periods to let your skin and neck adapt. Remove it immediately if you feel dizziness, tingling, numbness, or increasing pain. These are signs that the position may be wrong or that the collar is pressing on a nerve or blood vessel — in that case, stop using it and consult a specialist.
For travel, it can be used during a flight or a long car ride as extra support, but you should still be able to look around for safety. The same applies to any situation where you move from sitting to standing: the collar limits turning, not just bending, so give yourself time to move carefully.