Located in Glenwood, Ill., HomeBuyer s Preferred, also known as HPI, is a wholly owned subsidiary of Landauer. Established in 1993, HPI is a provider of radon protection plans for the relocation industry. It arranges short-term radon testing programs. The company sells alpha track radon gas detectors under the brand name Radtrak. HomeBuyer s Preferred provides postmitigation testing for the residential clients to confirm the radon concentration. It additionally offers installation and technical support services. The company s Web site offers online service request forms for the customers. Its parent company, Landauer, is one of the leading providers of radiation analysis, data management and dosimetry services for health care facilities universities, laboratories and nuclear power plants.