The basics done better, JELD WEN V-2500 Series Vinyl windows are made to be durable, energy efficient and attractive for many years to come. Classic colonial architecture meets modern ventilation and ease with double-hung windows. Both the top and bottom sash move up and down creating maximum options for air flow as well as tilt in for easy cleaning. Nail fin frames are ideal for new or replacement construction in a typical wood frame structure - commonly referred to as stick-built construction. Nail fins can be easily removed for pocket or block frame installation into wood, concrete or masonry walls with little disruption to the interior and exterior trim. Coated with a microscopic silver layer, LowE insulating glass lowers energy costs and helps homes stay cooler in the summer and warmer in the winter by reflecting sunlight away from the home in hot weather and heat back into the home in cold weather.