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A set of Trimm headphones manufactured by Trimm Radio MFG Co. Chicago USA. |
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A set of Trimm Dependable headphones manufactured by Trimm Inc. Libertyville Illinois USA. |
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Another set of Trimm Dependable headphones manufactured by Trimm Inc. Libertyville Illinois USA. |
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A set of headphones manufactured by the Federal Telephone and Telegraph Company of Buffalo NY USA. The model number for these headphones is Type 53-W and they are 2200 Ohms. |
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The photograph on the left is a set of headphones manufactured by Telex and the model number of these is 6101. I believe these have an impedance of 6000 Ohms. The picture on the right is a headphone and microphone combination manufactured by Western Electric Bell Systems and having a model number of 52. |
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