BigBoss A-Frame signs for visitor parkingare made from 160 mil thick corrugated plastic (sign panel). The sign panel is designed to fit into a heavy-duty thermoplastic frame with a contoured profile to deflect wind up to 30+ mph. You can add sand or water (or a mix of both for the heaviest option) to the ballast ports situated at the base of the A-frame for greater stability. EZ-Grip frame has built-in wheels on both sides for effortless rolling. The entire assembly is wide and sturdy, suitable for outdoors.