the t.bone freeU HT 823 Handheld, Replacement Handheld Transmitter, Suitable for freeU HT 823 (article no. #405079# - not included), Dynamic capsule, Supercardioid, Frequency range: 50 - 16,000 Hz, 4 Pre-programmed frequency groups with 4 available channels each, Auto squelch, Frequency scan in the receiver, 10 mW transmission power, Infrared settings transfer from the receiver to the transmitter, Pilot tone, 125 kHz grid, Modulation type: F3E, Dynamic handheld transmitter with metal housing, LCD display, Operates on 2 AA batteries or rechargeable batteries, Frequency band: 823 - 832 MHz@+*Note:* In this frequency band a maximum of 4 systems can be operated simultaneously.@+@+