Casement windows are side opening and can catch the breeze and direct it inwards. Like awning windows they can be used in most positions but are not recommended where windows open on to pedestrian areas. Be careful about positioning casements that open to catch the breeze in exposed positions as they may slam wide open in strong gusts. Restrictor stays can limit the opening in these situations. Special friction stays are available to allow wide 90 ° opening. The optimum maximum size is 1400mm high x 700mm wide.