Impact resistant solid vinyl frame and sash, fully welded. Low E 1/2" insulated performance glass, 2.78 R-value, 0.3597 U-value. Both sash operate and are removable. Fully weeped frame for efficient water removal. Extruded vinyl masonry fin. Extruded finon sill for mortar grab. Fully weather-stripped. True interlocking sash. Hook latch lock for positive sash to sash engagement. For new construction or replacement applications. Includes full screen and installation instructions. 2-1/4" frame thickness.