rotary engines of advanced and unusual design were produced under the Siemens-Halske brand, like the Siemens-Halske Sh.I and Sh.III. Later, Siemens established several company subsidiaries for which the Siemens & Halske AG functioned as a holding company. During the Second World War, Siemens & Halske employed slave labour from concentration camps. Among other things, they produced field telephones of the type "Feldfernsprecher 33" See also Siemens Siemens-Schuckert References External links Siemens Defunct aircraft engine manufacturers of Germany Werner von Siemens Ravensbrück concentration camp Companies involved in the Holocaust