Crank Open Casement Windows are American style window with a foldable handle and Rich Natural wood interiors in pine, oak, leak or prefinished by various colors, the window frame is protected by extruded aluminum profile for weather resistant. The window is hinged on the left or right and crank open outward and allowing for full top to bottom ventilation. It is designed with a lot of glass area with a narrower frame to provide an unobstructed view and often used in combinations with picture window to maximize the view. The hinged design creates an airtight seal when the sash closes against the window frame with proper weatherstrips and prevents air leaks. Simulated divided lites are a very popular design to create a classical appearance and comfortable feeling. The fold down handles provide a streamlined look and fold away to save space. The mesh frame uses a pin-less operation system to make screen removal and replacement easy. Crank Open Casement Windows are the most popular replacement choices for American homeowners due to the good energy efficiency, excellent ventilation capabilities, easy cleaning and no falling risks. All these make Crank Open Casement windows meet or exceed industry standards for performance and energy efficiency. Based on our previous test, the U factor is 0.27 for our recommend configuration of double glazing. Sure, We are able to supply customized options to suit your own energy efficiency by updating some options like triple glazing, replace spacer into warm edge spacer and advanced Low-E glass. In short, Doorwin Windows is able to supply a wide range of windows in different sizes, shapes and style. Here I will show you some details in bellowing.