1. The inside and outside of the window's glass clip are designed in cambered, it looks extractive and gliding and has a strong visual effect.

2. The duck-mouth is designed into the connecting of window's sashes and frame, which makes it has two isotonic entrails in the inside and outside. The capability of airproof and waterproof reaches Grade 5 of the government standard.

3. The design of rabbet adopts the European standard and it connects with active corners, the accessories is very simple that it can saves material and manual work, and nice-looking of the corner. It is easy to assemble that makes it convenient for the mass production.

4. The outside frame can install aluminum cover, it is accorded to the nice-taste of European, American, Middle East people.