All Rusco® Hung Windows are thermally welded at the frame and sash. The welding leaves a flawless, smooth finish and a complete unit. Rusco® Hung windows are fitted with cutting-edge drainage chambers that allow water to run through the external screen and back outside. Rusco® Hung windows all carry a stainless steel coil balance support system. The coil balance assists you as you slide the window up and down and it keeps the sash upright when required. Rusco® Hung windows can be tilted inward for easy cleaning year-round. Rusco® Hung windows can be fitted with double Pilkington Hard Coat Low E Argon Glass. The double pane unit is 7/8″ thick. Quality to last a lifetime!