Hartmann & Braun 1-amp. hot-wire ammeter | National Museum of American History
Peha®-instrument Operating Scissors
Voltmeter and calibration meter, Hartmann & Braun 1920-1930 - Catawiki
1942 Hartmann & Braun (H&B) 500 Volt Meter Insulation Tester. (Untested) Germany | eBay
Complete Catalogue of Electrical Measuring and Test Instruments Manufactured by Hartmann and Braun (Classic Reprint): Hartmann and Braun: 9781333433789: Amazon.com: Books
Hartmann Tuning Fork C-128 | Ear Instruments
WW2 German, Soviet, Allied militaria, uniforms, awards, weapons history. War relics forum