McGrath RentCorp, a business to business rental company, engages in the rental and sale of relocatable modular buildings, electronic test equipment, and liquid and solid containment tanks and boxes in the United States and internationally. It operates through four segments: Mobile Modular, TRS-RenTelco, Adler Tanks, and Enviroplex. The Mobile Modular segment is involved in the rental of modular buildings designed for use as classrooms, temporary offices adjacent to existing facilities, sales offices, construction field offices, restroom buildings, health care clinics, child care facilities, office space, and various other purposes; and portable storage containers. The TRS-RenTelco segment rents and sells general purpose electronic test equipment, including oscilloscopes, amplifiers, analyzers, signal source, and power source test equipment for aerospace, defense, electronics, industrial, research, and semiconductor industries. This segment also provides communications test equipment comprising network and transmission test equipment for various fiber, copper, and wireless networks to manufacturers of communications equipment and products, electrical and communications installation contractors, field technicians, and service providers. The Adler Tanks segment engages in the rental of fixed axle steel tanks for the storage of groundwater, wastewater, volatile organic liquids, sewage, slurry and bio sludge, oil and water mixtures, and chemicals; vacuum containers for sludge and solid materials, and for on-site storage or transporting materials off-site; dewatering boxes for separation of water contained in sludge and slurry; and roll-off and trash boxes for temporary storage and transportation of solid waste. The Enviroplex segment manufactures and sells modular classrooms directly to public school districts and other educational institutions in California. The company was founded in 1979 and is headquartered in Livermore, California.