This is for the Bahnschutzpolizei ORs tunic. The BSP came under Reichsbahn control for their regular service duties. For specialist service, eg concentration camp deliveries, they were under Himmler's hand.

These are two different examples of Schutzpolizei collar tabs, introduced in the uniform changes of 1936. The Schupo were a truly national force, as opposed to the Gendarmerie/Landespolizei (countryside) and Gemeindepolizei (town police). They, like the Ordnungspolizei, lived in barracks, a little bit like the Guardia Civil of Franco's Spain.