It uses a hydrophilic cloth as filtering medium. It can prevent the filtering layer from being blocked by super fine particles and can be used fro the dehydration of construction concrete and other kinds of slurries. Compared with other ordinary penetration tubes, it does not easily become useless because of being stifled by small particles(normal tubes are blocked in 3 hours of filtering). The high strength terylene silk makes the covered layer combine with the spring circles into one organic body with an omnidirectional filtering function. The water goes into the tube and the sand and soil are blocked out. It could be made into 10m or 20m pieces according to actual demand of project with the other end enclosed with IZl. Penetration, filtering and drainage are done at one turn.Geocomposite Drain.