Available in both aluminum and stainless steel, Ideal Products WeatherJacs® elbows are precision-formed in a state of the art; computer-controlled hydraulic press, which produces half shell pieces in 45 & 90-degree angles. All WeatherJacs® are dimensionally formed in conformance to ASTM C-585 and C450 standards. WeatherJacs® are designed with a patented weather seal system to help prevent water intrusion and mitigate CUI (corrosion under insulation) issues.