The Historic One Lite (HOL) series is designed to be “invisible”, - when painted the same color as the existing sash. All existing sash should be operable, to permit removal and/or cleaning from the interior. There is no hardware on the exterior. Typically, one or two panels are removable from the interior, and are secured by perimeter clips.
This operating unit has the same exterior appearance as the (HOL-B) unit. The top area is fixed, and the bottom panel is part of an operable and an interior-removable assembly. A lower screen is an integral part of this assembly. This unit provides ease of ventilation, - without interchanging panels.