Overhead Door Corporation's side-folding full closure grilles are ideal for applications that require a secure barrier against theft and debris, such as retail applications in malls and airport concourses. The Full Closure side folding grille product line includes four panel materials perforated steel, clear polycarbonate, tempered glass and aluminum. All four models are available in both standard-body and wide-body versions. Series 677 Lexgard™ -- Clear polycarbonate for visual access and nonbreakable durability. Visibility: 100% of 4-3/4" (121mm) viewable area.