This is a nice example of the Kriegsmarine 'Blockadebrecher-Kriegsabzeichen' (Blocade Runner Badge). The Blocade Runner Badge was instituted by Adolf Hitler on 1 April 1941 for award to Naval personnel and Merchant marines who met specific criteria, the most important being returning a ship to Germany  after breaking through an enemy blockade. The badge is executed in 'Feinzink'. The pin & catch are of course complete and functional, the badge is having an unusual questionmark shaped catch, nice variant. The zinc-type badge is not visible maker marked but can most likely be attributed to the company of 'A. Rettenmaier' from Schwäbisch Gmünd. Nice original example in good used condition!