Four NSDAP Quarterly Membership Dues Stamps. Issued from 1939 till 1945.
Good for Membership Cards and Books. Proof of the membership dues paid to the party. 
Avalilable in the following denominations: RM 2.40, 3.90, 5.40, 6.90, 9.90, 12.90, 15.90, 24.90 (they included Hilfskasse donation of 0.30RM)
 
All stamps can come clean, or stamped "NSDAP bezahlt" (they would be normally stamped if in a book or card).
 
Depending on number of factors your dues would differ. In principle, if
you joined before 1. April 1933, you'd pay 1.50 a month, or 1 per month when unemployed
for later members you'd pay depending on your household's monthly salary
<200: RM 1.5
<400: RM 2
<600: RM 3
<800: RM 4
<1000: RM 5
>1000: RM 8
for members in particular hardship, the dues would be reduced to RM 0.5
If you want to know more about NSDAP membership dues check out my blog article on that topic!