The super-pursuit type was not a secret, but Ernst Heinkel preferred to work in private and publicly display his products only after they were developed sufficiently to make a stunning first impression. As an example of this, the mock-up for the extremely modern-looking He 100 was the subject of company Memo No.3657 on 31 January that stated: "The mock-up is to be completed by us ... as of the beginning of May ... and be ready to present to the RLM ... and prior to that no one at the RLM is to know of the existence of the mock-up."