Experience top performance on a budget with the specially designed RELIABILT 105 Series single hung window. The bottom sash is easily removable and operates smoothly with dual lift rails. Ideal for new construction and remodeling projects, this window is easy to install with its pre-punched, integrated nail fin and built-in accessory channels. (Series 3050 is also available without nailing fin). With a DP-50 rating (Design Pressure rating) on windows up to 36-in W x 74-in H, this window is built to last. Additionally, its modular sizing allows for easy calculations of rough opening widths for multiple units. Made with Low-E glass to reflect solar energy and featuring the added thermal efficiency of Argon insulating gas, this window may not qualify for ENERGY STAR in all zones. For exact specifications, check each window's U-Value and SHGC value.