Complex sentence: During World War II, McMichael produced a wide variety of radio equipment for the war effort and was an early pioneer in the manufacture of sonobuoys, many thousands of which were used by the Royal Navy and Royal Air Force.
Split into simpler sentences: During World War II, McMichael produced a wide variety of radio equipment for the war effort. After the war the company manufactured thousands of sonobuoys for use by the Royal Navy and Royal Air Force.