Wall Mounted Telephone Apparatus
Device with induction calling and micro-telephone headset. The microphone used 0.3mm-1.0mm carbon balls. The existing model, with separate microphone and speaker, was taken as a guide but the top part (with microphone) was removed. In this way, with the installment of a micro-telephone headset, the quality of received and transmitted information was significantly improved. Used in Germany in postal services, military and government institutions, as well as by private individuals.