This device is specially made for settling ponds and water transfer systems. It allows for water control on the upstream side of water flow to pass into a buried HDPE pipe. They are constructed with stainless steel and are customized to fit your needs. Established in 1978, we are a design build commercial swimming pool and filter system company located in Pittsburgh, Pennsylvania. Ecol-O-Pack Systems, Inc. (ESI) specializes in stainless steel gutter systems, stainless steel spas, plunge pools, filter systems (built onsite), and new construction of stainless steel swimming pools.