Graphically demonstrate the key concepts of water treatment. Gives a firsthand view of physical, chemical, and biological processes comprising sewage remediation. Build a water treatment plant, complete with filtration, aeration, and bioremediation capabilities. Plastic model comes complete with everything to test and treat water. Includes Teacher's and Student's guides. Size is 13 1⁄4L x 4 1⁄2W x 17 1⁄4H".