Kolbe.
With a U-factor as low as 0.19, triple-pane aluminum-clad Ultra Energy Performance casement windows meet Energy Star certifications throughout the United States and Canada. Pine frames are standard, but multiple wood species are available. The casements have a standard 3 1/4-inch jamb depth and a 2 1/4-inch-wide sash. 800.955.8177. www.kolbe-kolbe.com.