1. The vinyl frames and sashes on the Sheffield window will never chip, peel, crack or warp. They are made with solid PVC resin.
2. The insulating chambers are airtight and reduce conduction.
3. Features a Quad 4 weatherstripping at the header for more protection from the elements.
4.  The insulated glass unit is double strength glass.
5. The PPG Intercept Warm Edge Spacer Systems maximizes window performance.
6. The interlock at sash meeting rails create an air-tight seal to prevent air infiltration and provide security.
7. The meeting rails have metal reinforcement to add strength.
8.  Drop-in glazing for energy efficiency and aesthetics.
9. The Sheffield features a compression bulb seal at the sill for all season weather blockage.
10. The sloped sill helps ensure water drains away from your home.
11.  The hidden screen track provides clean lines.

In addition: The Sheffield Double Hung also has dual ventilator locks, full balance covers, a constant force balance system, tilt-in top and bottom sashes, and fiberglass screens.