The 9490 Double Hung Series models include Double Hung and Double Hung combined with a T-mull for twins and triple hungs. Subtle accessory grooves come standard. The product accepts 3/4- and 7/8-inch insulating glass. The sill is engineered for high water performance with a 7-degree non-weep slope sill. The exterior simulates a 1- by 4-inch flat casing. T-Mullion system provides a continuous head and sill. The windows have dual weatherstripping at stiles, interlock, head and sill. Booth #2003.