- A high-quality, durable double-hung window made from Pella’s proprietary fiberglass material 
- NaturalSun Low-E glass allows the sun’s heat to flow in to warm your home and insulates from the cold; it blocks 94% of UV rays 
- Backed by a national brand with one of the strongest warranties in the industry 
- Low-maintenance frame made of the strongest material for windows*, featuring an energy-efficient foam-filled sash and frame for added comfort *Pella’s proprietary fiberglass material has displayed superior strength over wood, vinyl, aluminum, 
- wood/plastic composites, and other fiberglass materials used by leading national brands in tensile and 3-point bend tests performed in accordance with ASTM D638 and D790 testing standards 
- Exclusive cam-action lock design improves the security of the window and creates a stronger seal by reaching out and grabbing the opposing sash and pulling it into the other sash 
- A cam-action lock reengages the sashes and pulls them against the weatherstripping to ensure a reliable weathertight seal 
- For added strength, durability and reliable water performance, Pella Impervia products are secured with corner locks, metal fasteners and injected with sealant 
- Ready to install and completely assembled with a versatile nail fin design; slide in fin can remain on the unit for new construction applications or be removed for block frame replacement applications