Encouraged by their first experimental engine, which produced 16 W of shaft power from a bore and stroke of 30 mm × 25 mm, various development models were produced in a program which continued throughout World War II.
Încurajați de primul lor motor experimental care a produs 16 W putere și mișcare 30mm × 25mm, o variate modele de dezvoltare au fost produse într-un program care a continuat de-a lungul celui de-al Doilea Război Mondial.