1-piece steel roll formed frame that is bonded for strength against bending. Heavy-duty 1-3/4" hat section frame. This 1-piece bonded frame keeps patio screen rigid for easy rolling, and reduces track jumping and bending. Adjustable hood on top and bottom fits door openings 77-5/8" to 80". Top and bottom spring-loaded steel ball bearing wheels for smooth and lasting operation. Locking handle made of UV-resistant plastic. 2 heavy-duty 1" crossbars located 1 above and 1 below handle for added strength. Vinyl bug lap to seal patio screen against glass door. Charcoal fiberglass screen.