HelioVolt Corporation was a privately held U.S. solar energy company based in Austin, Texas, that suspended operations in 2014.
 The company manufactured photovoltaic (PV) solar modules using a thin film semiconductor process based on copper indium gallium selenide (CIGS) to produce CIGS solar cells. HelioVolt manufactured these thin film modules for commercial rooftop, utility-scale ground mount, residential, building-integrated photovoltaics (BIPV) and custom installations.
 The company raised over $230 million in investment, including over $80 million by SK Group.
Platt Brothers, also known as Platt Bros & Co Ltd, was a British company based at Werneth in Oldham, North West England.
 The company manufactured textile machinery and were iron founders and colliery proprietors.
 By the end of the 19th century, the company had become the largest textile machinery manufacturer in the world, employing more than 12,000 workers.
Caterham Cars is a British manufacturer of specialist lightweight sports cars established in Caterham, Surrey, with their headquarters in Crawley, Sussex.
 Their current model, the Caterham 7 (or Seven), originally launched in 1973, is a direct evolution of the Series 3 Lotus Seven designed by Colin Chapman.
 In the 1990s the company made the Caterham 21, a two-seater soft top alternative to the MGF and Lotus Elise, (which both sold many more units).
 A track-only car, the SP/300.
R, a joint project with Lola was released for customer testing in 2010 and was scheduled for release in 2013.
 On 27 April 2011, Team Lotus owner Tony Fernandes announced that he had purchased Caterham.
The Caterham 21 is a two-seat roadster designed and hand built by Caterham Cars in the 1990s.
 It was based on the mechanicals of the Caterham 7 and was intended to be a more practical version of that car with more conventional sports car styling.
The J. G. Brill Company manufactured streetcars, interurban coaches, and buses in the United States for almost ninety years.
 The company was founded by John George Brill in 1868 as a horsecar manufacturing firm in Philadelphia.
 Over the years, it absorbed numerous other trolley-interurban manufacturers such as Kuhlman in Cleveland and Jewett in Indiana.
 With business diminishing, in 1944 it merged with the American Car and Foundry Company (ACF) to become ACF-Brill.
 It ceased trolley and bus production in 1954, though some of their interurbans served the Philadelphia area till the 1980s.
 Brill was the longest lasting of the nation's trolley and interurban manufacturers.
 It manufactured over 45,000 streetcars, trams (also known as trolleys or trolley cars in the U.S.), motor buses, trolleybuses and railroad cars.
 At its height, it was the largest manufacturer of streetcars and interurbans in the U.S. and produced more streetcars and interurbans and gas electrics than any other manufacturer.
WangDAT was a magnetic tape data storage company founded in 1988 by Ben C. Wang.
 This was Dr. Wang's third startup company that he founded that manufactured tape drives.
 The company manufactured Digital Data Storage drives, which store computer data on Digital Audio Tape media.
 The company was acquired by Rexon in 1991.
Automobile Products of India (API) was founded in 1949 at Bombay (now Mumbai), by the British company Rootes Group, and later bought over by M. A. Chidambaram of the MAC Group from Madras (now Chennai).
 The company manufactured Lambretta scooters, API Three Wheelers under licence from Innocenti of Italy and Automobile ancillaries, notably Clutch and Braking systems.
 API's registered offices were earlier in Mumbai, later shifted to Chennai, in Tamil Nadu.
 The manufacturing facilities were located in Mumbai and Aurangabad in Maharashtra and in Ambattur, Chennai.
 The company has not been operational since 2002.
The Meriden Firearms Company of Meriden, Connecticut, USA manufactured small arms from 1905 to 1918.
 Meriden manufactured 20 varieties of hammer and hammerless revolvers with an output of 100 handguns a day in 1906.
 In addition to revolvers the company manufactured shotguns and rifles.
Walker Electric Trucks were battery-powered vehicles built from 1907 to 1942 in Chicago, Illinois and Detroit, Michigan.
 Initially designed and manufactured by the Walker Vehicle Company (not to be confused with the Walker Motor Car Company) in Chicago, they were bought by the Anderson Electric Car Company of Detroit in 1916, then sold to Commonwealth Edison of Chicago in 1920, and last to York & Towne in 1933.
 In addition to the trucks the company manufactured the Chicago Electric Car.
 Several of their trucks were long in service, surviving the brand, in some cases, by decades.
 A few of them are now on display in museums or, in the case of one exported to New Zealand, still "in service" with its original owner Orion New Zealand Limited.
The Lotus Elise is a two-seat, rear-wheel drive, mid-engined roadster conceived in early 1994 and released in September 1996 by the British manufacturer Lotus Cars.
 The car has a hand-finished fibreglass body shell atop its bonded extruded aluminium chassis that provides a rigid platform for the suspension, while keeping weight and production costs to a minimum.
 The roadster is capable of speeds up to 240 km/h .
 The Elise was named after Elisa, the granddaughter of Romano Artioli who was chairman of Lotus and Bugatti at the time of the car's launch.

Question: What BRitish company manufactured an alternative to the Caterham 21?
Answer: Lotus Cars