The 1/2" & 9/16" Gator Lock socket is required to install and remove blots and nuts from the 5/16" center hole models. Protects public safety by deterring theft and vandalism of critical traffic signs. Reduces cost and labor of replacing stolen signs. Maintenance-free locking system secures signs. Easy on, easy off with proprietary thin-walled socket. Eliminates the retrofit expense to safely secure lag screws in wooden posts. Holds signs securely during high winds with less wobble than other systems. Lock sold separately. 1/4" drive compatible.