Flex-Drain 51910 Flexible/Expandable Landscaping Drain Pipe, Perforated, 4-Inch by 12-Feet Pipe unfolds and expands from 15-inches to 12-feet Perforated pipe is for ground water drainage (French drains, dispersing water from flower beds) where soil is coarse Exceeds all applicable ASTM Standards Compatible with most traditional 3-inch and 4-inch corrugated pipe and 4-Inch PVC 30-Percent higher load-bearing rating than standard corrugated pipe