1. This kind of product uses the rolling-up sliding system is inside-till, no noise; It is easy to operate and very flexible.

2. It uses the airproof water strips which greatly improve the performance of airproof and is convenient to change.

3. This kind of window can be leant at a definite angle inside, this is easy to refresh the air slowly and is also convenient to learn the glass.

4. The window is of high intensity and safe to use, it is strong and durable so that it is good to be used in high building and civil domiciles.