Casement windows have outward or inward opening sashes hinged at the side. A pair of casements can close over each other without a central mullion.

Sashes are latched with a single, centrally positioned locking handle that operates a perimeter locking mechanism. Safety stays can be added for additional security.

With fusion-welded corners for weather-tightness as opposed to “screw together” aluminum joinery.

Multiple chamber system design enhances heat and sound insulation properties.