Hitler Created a series of three awards n 20th April 1939 Know as the Nazi party long service awards. To quality for an award you had to have served a requisite number of years in a relevant NSDAP organisation. These included, SA, SS, NSKK, NSFK, NSBO, NSKOV, DAF, HJ, BDM and the korps of political leaders. The first awards were presented in 1949 but were backdated, for example service before 1933 was counted as double the years. Using this method it was possible to earn the 25 year medal despite the party only been in power since 1933. Despite Hitler youth and Bund Deutsche maiden members been eligible it was only awarded to adult members.
The award itself comprised of a bronze cross for 10 years, a silver and blue enamel cross for 15 years and a white and gold enamel for 25 years service. The cross was made in three parts with a separate eagle and swastika to the front and the legend
Treue Fur Fuhrer und volk (loyal leader to the people) on the reverse. A length of ribbon was attached by the usual loop arrangement. These awards were unmarked but the main manufacturer is know to be Wilhelm Deumer (RZM code M1/120) of Ludenscheid . A well know manufacture of awards and badges.
I consider this to be a very attractive award and often overlooked. Below is a 10 years award from my own collection. A late issue example. These are quite common and (to be expected) with the 15 and 25 years much rarer.