The Flex-Drain 4"x12' Black Expandable Solid Flex-Drain. Its soil-tight fittings and shape-holding design eliminate the need for additional connectors, simplifying installation. Simply dig the trench, lay the pipe, and cover it up. This durable pipe meets the Corrugated Polyethylene Pipe Association's Test for Crush Resistance, ensuring longevity. Comes in a convenient pack of 6.