This is a rare Whermacht OB43 "Feldfernsprecher" field telephone. The OB stands for "Ortsfesten Betrieb" or fixed location. The telephone was a late war simplication of the standard FF33 field telephone and lacked weatherproving and provisions for carrying. It was intented to be used indoors in fixed positions. You can read a full description in our free book from page 36 (click on the link to open). The telephone is in good complete condition, the red tag on the lid is slightly faded.