Open the first window first, use both hands when opening, pull the child's safety lock pin, and rotate the handle with one hand to make it easier to open.
When you open the second fan, both hands rest on the middle of both sides of the window sash and go to the opened side of the sash, "open close to" and open, and so on.
Open sashes must be fixed with bolts to prevent wind and children from colliding, causing damage to the glass when violent shaking occurs.
When wiping the window sash facade, the sash must be opened at ninety degrees. The glass is cleaned with a glass cleaner, a soft cloth or a wiper to keep the sash clean and bright.
Protect the seal between the sashes. If stains and dust are present, use a soft cloth dampened with water or alcohol.