Bömish-Maerische Maschinenfabrik was the name given to the Czechoslovak CKD when Czechoslovakia was invaded by German forces in 1938, and the factory had to manufacture engines of German origin.

-At the end of WWII it was nationalized again, to continue manufacturing products such as from Czeschoslovak Metal Engineering Works in Jinonice.

-Later, the whole Czechoslovak aviation industry would be regrouped in Czeskoslovenska Zavody Automobilove in Letecké, Prague.

-In 1956 they presented the 220 hp Doris B engine (commercialized by Omnipol).

-Read on a characteristics plate:

“Erste Bömisch-Mährische Machinenfabrik”
“Praga” - Praga