SmartSign Sign Attachment Kit, "Attachment Hardware for Posts", 2.5" high x 0.3125" wide, Silver COMPATIBILITY. Compatible with our heavy-weight u-channel posts and square galvanized posts. Please note the 2.5" bolt maybe too long for some applications. For a shorter bolt please see our updated kit (K-Kit-2), which includes both 2.5" and 1.5" bolts. This Updated kit gives you the flexibility to fasten a sign to either medium weight (1.12 pound/foot) or heavy-weight municipal (2 pound/foot) posts. EASE OF USE. Fasten signs easily and securely. INSTALLATION. Easy to install with an adjustable wrench. DURABILITY. Zinc-plate steel does not weaken - hardware is rust-proof and weatherproof. PROVEN. This is the same hardware that is sold to 1,000s of our municipal and governmental customers for parking and traffic signs.