These Barricades are built from heavy gauge steel and are hot-dipped galvanized inside and out for long-term weather resistance. Frames are made from 1.5″ OD 16 gauge steel tubing, while uprights are made from 1/2″ OD 16 gauge steel tubing. Uprights are fully inserted into the frame before welding, providing extraordinary strength. Choose from two base systems: a bridge base for uneven surfaces such as grass and a flat base for smooth surfaces such as tarmac and where pedestrian traffic demands the minimum trip hazard. The barricades interlock using the industry standard hook and half-loop fastening system.