Beyerdynamic Synexis TH 8, UHF-transmitting microphone for the Beyerdynamic-Tour-Guide-Concept, 18 frequenzies selectable (863/865 MHz), with an electret-condenser-microphone-head, OLED-display, on-/off-switch, integrated antenna and two changable and recharchable AA 1,2 V/2050 mAh NiMH-batteries