The TD5500 Ground Mount Delineators are designed to be flexible, impact-resistant and able to withstand the extremes of hot or cold weather. The Earthflex posts are anchored into the soil via galvanized steel anchors in closed end, open end or PSST (square post) configurations. A unique hinge system allows the TD5500 posts to return to the upright position after repeated high speed impacts.Sheeting sizes to your specifications. All sheeting complies with ASTM 4956.01 standards.