| Windows & doors type ventilating opening with polished design suitable for interior.Windows & doors type ventilating opening New Type- Refined design, most suitable ventilating According to ventilation quantity, it is convenient to adjust the opening & closing quantity of slide, the opening & closing of the middle part of frame is possible, so this is effective ventilating opening for quality increase of indoor air.By harmonious ventilation of the outside & inside, please enjoy fresh indoor air.- Main characteristics1. The opening & closing is possible in the frame middle of outside windows & doors top & bottom.2. Natural ventilating opening for quality increase of indoor air.3. Sliding cover is attached on the inside cover to adjust ventilation quantity.4. Composed of outside verver penetrated by minute hole, not to enter the worm.5. Color : can select color freely.6. Product manufacture according to the standard for each manufacturer of windows & doors profile. | 
