Concentrated photovoltaic trackers are used with refractive and reflective based concentrator systems. The thin polymer layer acts like a concentrator that absorbs gaseous molecules. The best known of these devices is the CPC (Compound Parabolic Concentrator). Home oxygen can be provided either by oxygen tanks or an oxygen concentrator. POCs operate on the same principle as a home concentrator, pressure swing adsorption. It has two intensive care units, laboratories, an X-ray unit and a mobile oxygen concentrator. The resulting device is called a CEC (Compound Elliptical Concentrator). Individual local loop telephone lines are connected to a remote concentrator. In contrast to the power tower concentrator concept that California's original Solar One project uses. That unit was replaced with the first Acacia concentrator installed in North America. The high concentration ice is extracted from the concentrator. The phasor data concentrator runs as a Windows service. The copper is then taken to the concentrator. This focuses light from the large concentrator area down to the smaller cell area. Hatch was appointed EPCM contractor for the Brine Concentrator project.