The Hitlerjugend is typically a symbol under the IIIrd Reich. The youth, giving their lives for the people. 
The distinctive HJ belt buckle was introduced in 1933. The example we have is maker marked M4/22 with RZM stamp indicating a production by "Christian Theodor Dicke" in Lüdenscheid near Dortmund. 
The Buckle seems to have been used a lot but still shows nice details.