The Z300 Interlocking Bracket can be used to mount one standard center-to-center punched sign to a 3" OD round post. Each kit includes: 2 each large brackets .375" long with 5" mounting bar, 2 each small brackets 3.617" long, 2 each 5/16" x 5/8" bolt/nut sets, and 2 each 5/16" x 1 3/4" bolt/nut sets.