The He 111 was designed in the early 1930s to be a fast medium bomber that could be used as an cargo plane ti get around the limitation of the Versailles Treaty that prohibited Germany from maintaining an air force. It first saw active service as the He 111B in the Spanish Civil War with the Condor Legion where it proved to be a tough and dependable aircraft. Subsequent version of the aircraft were used by the Luftwaffe thoughout WW2 despite the fact that the basic design was obsolescent by 1943. A Spanish built version remained in service until the early 1970s.
The speherical depression under the model is for mounting it on a 6mm BB.