Capture and redirect adjacent groundwater to prevent saturation along foundations, surface flooding in the yard, and other costly water damage with the National Diversified Sales Ezflow EZ-0701F 7" x 10' Black Gravel-Free French Drain System with 3" Slotted Pipe. An alternative to traditional gravel-filled French Drain systems, the EZflow French Drain is easier to install and has a 30% better flow rate. The EZflow bundle is made of 3 in. single-wall corrugated pipe of high-density polyethylene (HDPE), centered and surrounded in Poly-Rock™ of expanded polystyrene (EPS), all encased in a black geotextile mesh sleeve. Hassle-free limited lifetime warranty guarantees the NDS product is free from defects—or we’ll replace it.