SmartSign Adhesive NFPA Sign Kit with Symbols & Letters, Legend "Laminated Vinyl Adhesive NFPA Placard Kit", 25.5" tall diamond (point to point), Black/Blue/Red/Yellow on White Signs conform to round tanks and stick permanently Digits are self-aligning Your NFPA Kit is a snap to assemble NFPA diamond, when measured from the top to bottom of the diamond, is actually 255" high (eg which is the same as the 18" square tilted by 45 degrees)