Gridmax is the low-cost alternative to replacing or repainting rusted, stained or deteriorated metal grid. Made from PVC vinyl. Class A fire rated. Rust and corrosion resistant. The pre-notched main covers provide seamless transitions at cross-tee intersections for easy installation. Designed to cover 2 ft x 2 ft or 2 ft x 4 ft ceiling grid systems. Snap-on Grid Cover works on 2 ft x 2 ft or 2 ft x 4 ft ceiling grid systems (15/16 or 1 inch).