Tour Guide Micro TX, UHF Guidance Systems Transmitter, Audio frequency response: 300 Hz - 3400 Hz, Radio frequency response 823-832 & 863-865 MHz, LCD Display, Integrated Li-Polymer (3.7 V, 1300 mAh) battery with a runtime of up to 16 hours, Integrated microphone, Connections: 3.5 mm TRS microphone input, Micro USB power connection, Lanyard, Weight: 50 g, Colour: Grey/Black