J-Drain® 302 consists of a heavy duty high density polyethylene geonet drainage core with its ridges heat fused to a layer of non-woven fabric. The filter fabric retains soil or sand particles as well as freshly placed concrete or grout, allowing filtered water to pass through to the drainage core. J-Drain® 302 is identical to J-Drain® 300 in physical properties with the addition of a layer of filter fabric to the back side providing drainage and filtration from both sides.