The Trona is a metal bodied folding plate camera, with double extension bellows, and screw controlled front rise and shift. Generally, it is encountered with Tessar lenses, although it was also offered with Dominar. Shutters are Compur, first dial set, and rim set after 1930. The Trona is identified on the handle area, with the Zeiss number on the rear of the top, embossed in the leather. The Trona was introduced in 1912 by Ica. When Ica merged with Goerz, Ernemann and Contessa Nettel in 1926 to form Zeiss Ikon, the line was carried over into the Zeiss catalog. It was initially cataloged under the Zeiss number 210, available as the 210/3 (6.5 x 9cm), 210/7 (9 x 12cm) and 210/5 (8.5 x 11cm). The last size was made for American and British markets only and is uncommon. The 210 series was dropped in 1930. In 1928 the 9 x 12 size became available as the 212/7 until it was discontinued in 1936. The final version of the Trona was the 214 series, introduced in 1929. It was a fancier version of the Trona, with an aluminum ground glass back (frequently exchanged for a regular back) that cost around $235.00 when new. It was offered as 214/3 (6.5 x 9cm), and 214/7 (9 x 12cm). This final version production ended in 1936 (1938 according to McKeown’s), as a war was brewing in Europe, and Zeiss began dropping models from their catalog without replacing them with new offerings.