According to the product description, this neoprene sleeve is designed for light stabilisation during sport, exercise, walking and guided activity. That means you can wear it for a training session, a bike ride, a longer walk, or general daily movement when you want the knee to feel more stable and warm. It is a flexible sleeve with no rigid parts, so it is not meant to immobilise the knee; it simply adds mild compression and warmth while you move.
There is no universal time limit that fits everyone, because how long you wear it depends on the activity and your own comfort. A practical starting point is to wear it for the duration of one activity, for example a 30–60 minute walk or workout, then remove it and check how the skin and knee feel. If there are no deep marks or discomfort, you can use it again as needed. Constant all-day wear is not necessary for a support whose purpose is activity, and wearing it overnight has no added benefit for most people.
Stop using it immediately if you notice numbness, increased swelling, pain, or any sign that circulation is impaired. If you are returning to movement after a break, or if the knee has been injured or operated on, speak with a medical professional first to confirm that a mild compression sleeve is appropriate for you. The product provides mechanical support only and does not replace medical assessment or treatment.