It all depends on your choice.

2. Metal amplifiers used in the structure can be of two types — P -shaped and square. In this case, the square are more reliable and durable.

3. The number of double -glazed windows in your frame. The double -glazed window (that is, the camera) in your frame can be either one, two, three, or even six. It all depends on your choice. Accordingly, the more double -glazed windows, the warmer and more comfortable you will feel in the house. We want to note that three -chamber double -glazed windows are great for an ordinary residential building or apartment, they will fully provide noise — and thermal insulation in your housing.