Made of durable outdoor-grade vinyl. May use fiberglass or aluminum screening. Can be cut with utility shears or tin snips. Paintable. No mitering. UV protected. Screen (not included) is rolled into place and cap snaps onto base (not included) and evenly tightens the screen without the use of staples, lattices, nails or loose screens. When rescreening, the cap temporarily pops off. 1-1/2 in caps are used to accommodate 2 in x 2 in framing and 3-1/2 in caps are used to accommodate 4 in x 4 in framing.