Flex-drain 50510 flexible/expandable landscaping drain pipe, perforated with sock, 25-foot a pipe with spaced slits, covered with removable polyester sock. Appropriate for ground water drainage (french drains, dispersing water from flower beds) in applications where surrounding soil or sand is fine enough to require filtration and/or surrounding debris is considerable. Works effortlessly with our complete system of connectors, couplers and adaptors. Exceeds all applicable astm standards. Made with no-break copolymers for professional grade strength and integrity. Proprietary peak and valley design offers greater surface area and a 30-percent higher load-bearing rating than standard corrugated pipe. Guaranteed not to split, crack or break when used in accordance with local building codes. Flex-drain is compatible with virtually all traditional 3-inch and 4-inch corrugated pipe and 4-inch pvc. All flex-drain products are made in america.