Plastic Lumber Speed Bump, 100% recycled Easy to install with lag bolts, you can now control speeding vehicles in your parking lots. Available in 9', 6' and 4' lengths. Installation hardware included Available in Yellow. What is plastic lumber made of? It is made from recycled plastic milk jugs, otherwise destined for a landfill. When using plastic lumber, you are helping the environment as well as utilizing a long-lasting, maintenance-free product. Quantity