Help prevent theft & increase work place safety with this security mirror. Scan unguarded aisles, eliminate blind intersections, monitor production areas & safeguard entrances & exists. Detection mirrors are curved to eliminate distortion. This adjustable, convex glass security mirror has a 160 view angle, making it ideal for scanning any business or office. For easy installation, all mirrors come with heavy-duty mounting brackets. Circular. Diameter: 18"; for Area: 15 sq ft; Shape: Circular; Convex; Material(s): Glass.