Cast iron detectable warning plates provide a durable solution for warning visually impaired people of pedestrian obstructions and hazards. Precision 2-foot square plates allow easy, accurate tiling for attachment. Cap head screws can be added for extra anchorage. Cast iron truncated domes are virtually indestructible and highly resistant to snow plow damage. Meets MNDOT and most county and municipal specs. Optional powder coated epoxy finishes are available: federal yellow, optimal white, brick red.