Adolf Hitler chooses the right-handed (counter-clockwise) swastika as the symbol for the NSDAP. This was the swastika form which had been used by the Thule Society and Guido von List.
Friedrich Krohn, a dentist from Starnberg and early member of the German Worker's party (Deutsche Arbeiterpartei, DAP) wrote a letter in 1919 entitled Is the Swastika Suitable as the Symbol of the National Socialist Party?.
A member of the the Thule Society and the Germanenorden since 1913, Krohn was the first to suggest use of the swastika by the DAP; he probably got the idea from the Germanenorden, which had used a swastika for quite some time.
Friedrich Krohn recommended the left-handed or clockwise swastika favored by Theosophists and the Germanenorden because Buddhists regard it as a symbol of good luck and good health.
Although Adolf Hitler does not stick with Krohn's original orientation for the swastika, he does use Krohn's overall design of a black swastika in a white circle against a red field.