Recommended adjacent to pedestrian traffic or where edge reinforcement is required for special mounting conditions or long term maintenance. #5104 Steel Channel Trim or #5105 Steel Edge Trim can be added to panels in multiple configurations, but is not necessary to maintain panel rigidity. Specifications: 5104: 1/2" leg x 3 1/8" wide x 1/2" leg: 20" gauge galvanized steel 5105: 1/2" leg x 1/2" leg: 20" gauge galvanized steel Specifications: 5104: 1/2" leg x 3 1/8" wide x 1/2" leg: 20" gauge galvanized steel 5105: 1/2" leg x 1/2" leg: 20" gauge galvanized steel