Each door features an extruded aluminum gusset system. This combined with .65″ thick high-grade aluminum rails and kick panel create a stable door that resists twisting and denting. Offered exclusively by HMI, Cam Lock System is free of loose parts and accessories making it hassle-free to replace your screen. Continuous Extruded Hinges, manufactured exclusively by HMI, surpass the quality and durability of anything else offered on the market. Extending from top to bottom, and reinforced with a stainless steel rod, the extruded hinges will never sag or warp from the weight of the door, thus ensuring a perfect fit every time you close your storm door. All doors are coated with a powder-coat finish to give years of trouble-free enjoyment. Steel Security Storm Doors are also available.