HHDO-18H. Made of lightweight, shatter-proof acrylic, this high reflective mirrored surface permits either 360°, 180° or 90° vision. 360° dome provides all-around viewing for 4-way intersections. 180° provides 3-way vision for "T" intersections, 90° dome provides 2-way vision for "L" intersections. Deters pilferage and requires no maintenance. Decorative domes blend in with any decor. Installs easily. FOB Shipping Point.