Pella 250 Series 47-1/2-in x 47-1/2-in x 3-1/4-in Jamb Left-operable Vinyl White Sliding Window Half Screen IncludedThe Pella 250 Series vinyl sliding windows are equipped with enhanced security and privacy features, allowing them to glide open effortlessly. These windows are made with dual pane SunDefenseTM Low E insulating glass filled with Argon gas, allowing for natural light to enter while blocking the sun's heat. One sash moves horizontally while the other remains still. Additionally, Pella's vinyl material is fade resistant and tested for exceptional