The FLEX-Drain 4 in. x 21 in. Polypropylene Connector is ideal for repairing damaged sections of pipe. This connector can expand to 21 in. and has flexible construction to create angles with ease. FLEX-Drain helps you get the job done faster and easier, with professional grade durability and more versatility than traditional corrugated pipe. Flexible and expandable, FLEX-Drain easily bends around any obstacle, hold its shape during installation and with a simple snap, its integrated soil-tight fittings lock securely and stay connected during backfilling. FLEX-Drain is a complete drainage solution system that's widely compatible with virtually all traditional 3 in. and 4 in. corrugated pipe and 4 in. PVC. Technologically superior, it's made with no-break copolymers and exceeds all applicable ASTM crush standards. Expands up to 21 inches to reach pipes that have been cut short and to help repair damaged sections of pipe.