Good Ideas GW-WALL4-DAR Garden Wizard Self-Watering Landscape Border, Dark Granite Single 4-Feet rock wall Takes the place of heavy, expensive, bricks Connects to all other Garden Wizard rock walls Can be upgraded using the Border Hose Kit Made of Polyethylene in the USA Single 4-Feet rock wall - BPA Free Takes the place of heavy, expensive, bricks Connects to all other Garden Wizard rock walls Can be upgraded using the Border Hose Kit Made of Polyethylene in the USA